Category Archives: collecting gems

Rough Roulette; Colombian Emerald Part II

By Richard W. Wise, G.G.

“Round and round she goes and where she stops, nobody knows.”

I have heard it said that each time you put an emerald on the wheel the chances of breaking the stone are about 50/50. I recall one hot and dusty afternoon in the late 1980s I was sitting with some friends at a cafe in Teofilo Otoni, a town which was, at that time, the gemstone capital of Brazil. A ragged looking garempiero rode by on a motorbike, turned around and rode back to the cafe. He knew my friend, a Brazilian cutter, so he pulled a dirty scap of cloth from his shirt pocket and let us have a look. The cloth contained an emerald crystal from the mines ant Santa Terezinha de Goiás. The miner had rode all through the night to bring his find to Teofilo. During the 80s Goiás produced emerald that rivaled some of the better gems Colombia had to offer. (pictured left: Entrance to the shaft at La Pita Emerald Mine. Guacharos wait for the tailings. Photo Richard W. Wise)

The perfectly formed hexagonal crystal showed a verdant medium-dark green color that looked exceptionally fine. I don’t recall the actual weight (somewhere in the 25 carat range) but the crystal was about the size of my index finger. This crystal lacked the jewel-like transparency of the Colombian crystals pictured in Part I and was difficult to evaluate. I could see the pepper like inclusions typical of of Goiás emerald but little else.

The asking price of the Brazilian crystal was a quarter of a million dollars. Long story short, I didn’t make an offer. I thought the crystal lacked the transparency necessary to evaluate it and I wasn’t prepared for a quarter of a million dollar spin of the wheel. I later heard that the crystal had been sold for something close to the asking price and that when it was put on the wheel it had literally exploded leaving the buyer with nothing to show for his purchase.

High Rollers:

Hurry, hurry, hurry and welcome to the high stakes world of the rough buyer where every parcel is a gambol. In this world, where a single bet may exceed a million dollars, the dealer across the table from me is a high roller. The parcel so casually scattered across the desk in front of me is a big time rise. Perhaps 1400 carats, it is from the new mine, La Pita, a complex of adjacent shafts in the Colombian state of Boyaca. One mine actually bears the name La Pita, the others are Consorcio, Cunas, Totumos and Polveros. In a country where the old mines have been producing since before the Conquistadors conquered their local owners in the mid Sixteenth Century, serious commercial mining only began at La Pita in 1997. (Pictured left: the author works his way through a half mile tunnel to the surface. Foreground, miner pushes cart full of mine tailings, these will be given to guacheros waiting at mine entrance for further sorting: Photo: Ron Ringsrud)

We are about to watch the fashioning of two of these crystals into gemstones. In this high stakes world a dealer needs an edge. Having a lapidary with the skill of Adolpho Argotty is just such an edge. According to Argotty, in his workshop, loss on the cutting wheel is perhaps 4% and that is perhaps why Argotty is rated the best. He is presently traiing the second generaltion, his niece, Fernanda, who sits at a wheel at his side (see image above right).

Argotty doesn’t just pre-form the stone he supervises the entire process:

“Would you ask an architect to just put up the bones of a structure and let others finish it?” he asks.

(images: above: Adolpho Argotty, holds forth: Picture Richard W. Wise) It takes just about a half an hour. Argotty works away the emerald held between his thumb and forefinger. He grinds a bit then holds the stone up and squints at it in the sunlight all the time carrying on an animated conversation in Spanish with my partner Ron Ringsrud. Ron loves Colombia. He deals exclusively in Colombian Emeralds, has been coming to Bogotá for twenty-five years and speaks fluent Spanish.

The workshop is surrounded by windows on three sides. The light is good. The two crystals have been blocked out, that is to say, they are now the size and shape of the finished gem. Argotty decided to cut the best crystal into a standard rectangular emerald cut. The stone started out at 7.17 carats it now weighs 4.77 carats and it is ready for the faceting wheel. Argotty is excited about this gem. He hands it to Maria Fernanda to polish the table, he wants a closer look.

She hands it back.

“This one”, he says, “will be worth at least $10,000 per carat.”

The second stone which began at 8.53 carats has been shaped into what Argotty is calling a rose cut. I am confused because the stone obviously has a pavilion and looks very much like an antique style emerald cut with overly large corners. Later we figure out the problem is in translation, Argotty means an old style cut which this stone obviously is. Even before polishing commences we see visible inclusions in the stone. It now weighs 6.44 carats.

Step #1 Sealing & Certification:

In Adolpho Argotty’s workshop, preformed stones are dipped into hot paraffin. The objective is to seal any surface breaking fissures to insure that no residue of the polishing compound makes its way inside the stone.

Colombian cutters become a bit testy when the subject of lab grading is raised. If you love emerald you must be prepared to accept some surface breaking fissures and yes, cedar oil is universally used as a treatment to hide these fissures. However, both dealers and cutters feel that they are getting a bad rap from some American and European Gem Labs. Most labs use a uniform four step grading process to grade the level of enhancement: none, minor, moderate and heavy. Gubelin adds insignificant between none and minor and AGL (American Gemological Laboratories) uses its own proprietary scale. Columbian Esmeraldaros believe that this system lacks consistency. The labs, they contend, are afraid to use the term none. According to Argotty, he has delivered emeralds that he personally cut and knows to be totally without enhancement, to major European labs which in turned issued reports claiming these emerald contained a filler. The reader should bear in mind that a certificate grade of none is in no sense a clarity grade,the stone can still look like a broken coke bottle. It just contains no filler, no clarity enhancement.

I examined hundreds of finer stones in the course of my week in the Bogata market and with but a single exception, every stone I saw had some surface breaking fissures. Taking Ron Ringsrud’s advise I rejected any stone with fissures on the crown or girdle or those with fissures on the pavilion that I felt might n anyway compromised the durability of the stone. This, by the way, would make a good definition of the term minor enhancement.

Next, Dopping, Faceting and Polishing. Stay Tuned.

Learn the truth about how Emeralds and other fine gems are graded and priced!

Follow me on gem buying adventures in the pearl farms of Tahiti. Visit the gem fields of Australia and Brazil. 1
20 carefully selected photographs showing examples of the highest quality gems to educate the eye, including the Rockefeller Sapphire and many more of the world’s most famous gems. Consider my book: Secrets Of The Gem Trade, The Connoisseur’s Guide To Precious Gemstones.

“Wise is a renowned author… He’s
done a marvelous job of this first book, monumental work, a tour de force…My recommendation: Buy this book”.

Charles Lewton-Brain, Orchid

whether you like to know what the best colour is in Tanzanite, or how to grade a Diamond, you will find it in this book. No other book I read before dealt with this topic is such detail as Richard Wise’s masterpiece.”

A. Van Acker, FGA
Amazon June 2005

“Secrets Of The Gem Trade: The Connoisseurs Guide To Precious Gemstones by Richard W. Wise is an impressive new reference for dedicated dealers and collectors of gems, gemstones, and … pearls. Introducing and descriptively exploring each and every gem covered in the easy-to-use reference, Secrets Of The Gem Trade contains an illustrated summary of each stone inclusive of its history and general information, hue and tone, saturation, which may be noticed as the finest, an understanding of the particular gems rarity, and the caution for synthetics and how to depict them, however depending upon the stone there may be description of clarity, color fading, multi-color effect, etc. Secrets Of The Gem Trade is very highly recommended to anyone interested in gemology as a superbly organized, authoritative, comprehensive, and easy-to-follow reference.”

Midwest Book Review
April 2006

Only $31.95. Read a couple of chapters online: www.secretsofthegemtrade.com.

Buy it on Amazon: www.amazon.com

Asking to see the Pigeon’s blood is like asking to see the face of God"

1 Reply

About once a month on one of the gem forums someone asks the question:

"What color is pigeon's blood."

by Richard W. Wise, G.G.

The real question is, of course, "what is the best color in ruby." Although I cover the question in some depth in my book; Secrets of The Gem Trade, The Connoisseur's Guide to Precious Gemstones, it appears that a few people have yet to read the book. (pictured above a gem quality 2.09 carat natural old mine Burma ruby with a GRS "pigeon's blood certificate)

The short answer is simply that rubies should be red. Problem is there are almost no visually pure color in nature so, we speak of a mixture of colors. In gems, we normally speak of a primary and a secondary color or hue. Gems may have more than two hues but it it is difficult for even the most discerning connoisseur to see more than two. Still a ruby must be predominantly red, that is, have a primary red hue. Put another way in the color mix, red must be at least 51% of the hue mixture. If its not red its not a ruby. Any member of the gem family corundum that is any color other than red we call sapphire.

Ruby may exhibit one of a few possible secondary hues. These are: pink, purple and orange. Purple and orange are the hues immediately adjacent to red on the color wheel. You will never find a ruby with a green secondary hue. Pink, a paler less saturated red is also possible. The finest color or pigeon's blood exhibits a purple secondary hue. Why purple, there are two good reasons; one historical and the other based upon color science.

This historical explanation I owe to Vincent Pardieu. Vincent began by studying gemology in Burma and he found a dealer who explained "pigeon blood" to him. The Burmese coined the term. Purple is a hue that falls between blue and red on the color wheel. It is known scientifically as a modified spectral hue.

The Burmese set gems in pure gold which is a a very rich yellow color. Blue is the compliment of red. Complimentary colors are those that cancel each other out. So when a purplish red ruby is set in yellow, the yellow of the metal cancels out the blue in the purple leaving behind, guess what an almost visually pure red.(pictured above a 1.63 carat gem quality old mine Burma ruby with a GRS "pigeon's blood certificate). So the goal for the Burmese is red, pure red! See more!

I wrote my book several years before I met Vincent in Bangkok. However, I reached the same conclusion by applying a logical analysis. My reasoning goes something like this. Color Science teaches that the color red reaches its optimum saturation (brightness) at a fairly dark tone, somewhere about 80%. This is not opinion, it is measurable scientific fact. If you consider that 100% tone would be pure black, 80% is pretty dark. Pink and orange on the other hand reach their optimum saturation at fairly light tones. Pink obviously as it is by definition paler (less bright). Orange reaches its optimum saturation at between 30-40% tone.

Purple reaches its optimum saturation at around 60% tone. Now, if you add a light pigment to a dark paint you would obviously lighten the overall effect. Same is true in transparent media. The optimum tones of red and purple mix fairly well both being both dark in tone. The purple unlike the pink does not dilute the red. Pink and orange would lighten the red thus reducing the overall saturation of the pinkish-red or orangy-red color. Purple reinforces the red, orange and pink dilute. Make sense? Not everyone agrees. Some connoisseurs like a bit or orange. They feel it frames and pumps up the red hue. A good point if you consider the effect of orange in red spinel. Be that as it may, for good historical as well as scientifically verifiable reasons, orangy red is not pigeon's blood.

The first image above is of a 2.09 carat Burmese natural ruby from the old min at Mogok. This stone has a bit purer red, exhibits less purple than the second stone, a 1.63 carat gem from the same mining area. Both, however, have been grading "Pigeon's blood" by GRS, Swiss Lab, Bangkok. As you might imagine this lab sees an awful lot of rubies. Both stones are from the Mogok Valley, this is the place, going back to the Bronze Age, where the original stones were mined back when the term pigeon's blood was coined. A lot of the gems currently in the market are from a new mining areas Mong Hsu that is about half way between Mogok and the Thai border. Mong Hsu stones can certainly be pigeon's blood color but since we are talking about a historical term I thought it best to use illustrations from the old mine.

With the discovery of new sources of ruby in Africa a controversy has arisen over use of the term pidgeon's blood to describe the color of gems most specifically from Mozambique. The Chinese have outright banned the use of the term for ruby other than those of Burmese origin.

At the 2012 Hong Kong show I purchesed two exceptional unheated gems from Mozambique that were described in a GRS report as "vivid red" with a color identical to Burmese stones with GRS Pidgeon's Blood certificates. If, as I have suggested here and in my book, pigeon's blood is a definable hue then it seems to me that any ruby that meets those criteria can and should be labeled the same.

Want to Learn more?

Follow me on gem buying adventures to the old Burma ruby mine at Mogok. Learn how to judge the quality of rubies, sapphires, emeralds, garnets and 31 other gems. 120 carefu
lly selected photographs showing examples of the highest quality gems to educate the eye, including the Rockefeller Sapphire and many more of the world's most famous gems. Consider my book: Secrets Of The Gem Trade, The Connoisseur's Guide To Precious Gemstones.

“Wise is a renowned author… He’s
done a marvelous job of this first book, monumental work, a tour de force…My recommendation: Buy this book”.

Charles Lewton-Brain, Orchid

A. Van Acker, FGA
Amazon June 2005

"Secrets Of The Gem Trade: The Connoisseurs Guide To Precious Gemstones by Richard W. Wise is an impressive new reference for dedicated dealers and collectors of gems, gemstones, and … pearls. Introducing and descriptively exploring each and every gem covered in the easy-to-use reference, Secrets Of The Gem Trade contains an illustrated summary of each stone inclusive of its history and general information, hue and tone, saturation, which may be noticed as the finest, an understanding of the particular gems rarity, and the caution for synthetics and how to depict them, however depending upon the stone there may be description of clarity, color fading, multi-color effect, etc. Secrets Of The Gem Trade is very highly recommended to anyone interested in gemology as a superbly organized, authoritative, comprehensive, and easy-to-follow reference."

Midwest Book Review
April 2006

Now 20% off. Read a couple of chapters online or buy one of the few remaining limited editons: www.secretsofthegemtrade.com.

Buy it on Amazon: www.amazon.com

Labels: gem prices, gemstones, new gem strike, spinel prices, Tanzania gems, Tanzanian Spinel

Gem Prices follow Real Estate in the New Gilded Age

Golconda Diamonds Part II

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The Legendary Blue-White Diamonds, Rarest of them All

by Richard W. Wise

Just recently it was my good fortune to examine one of the legendary diamonds of Golconda. These gems were originally mined in India in the 16th-18th Centuries. The mines were tapped out by about 1725. Many of the world’s most famous diamonds, including the Regent and the Sancy (pictured above right), The Hope and the Koh-i-Noor came from the mines of Golconda. This gem was accompanied by a GIA certificate rating it D Flawless, the highest possible diamond grade and a Gublin Laboratory certificate that identified the stone as a Type IIa. (Regent above left, Sancy above right)

As discussed in my previous post, recent scientific analysis has shown that diamonds with proven Golconda provenance are of a specific type of rare, pure carbon diamond known as Type IIa. Less than 1% of the world’s diamonds are Type IIa. Scientifically speaking, Type IIa diamonds are an almost pure carbon diamond containing no significant amount of nitrogen in the crystal lattice. Nitrogen is the impurity in diamond that imparts the yellowish hue. The lack of yellow makes for a pure colorless (D,E,F) color diamond. Some experts claim that all Golconda diamonds are Type II. There is, as far as I know, no scientific evidence to back up that claim.

Blue-White Beauty:

Golconda stones are the true blue white diamonds of legend. Today, dealers use the term blue white to describe diamonds that exhibit blue ultraviolet fluorescence. About 30% off all diamonds will exhibit this characteristic. Though ultra-violet fluorescence is not visible to the naked eye, though its effect may be. Blue is the complement of yellow, meaning that blue fluorescence in diamond effectively cancels out some of the yellow in the diamond’s body color. As a result, fluorescent diamonds will face up whiter than their actual color grade might suggest–a fluorescent H might look like a D color. It is UV fluorescence is also responsible for the super-charged saturation of very fine Burma-type rubies.

The gem I examined, a 9+ carat D-Flawless took on a distinct distinct bluish glow in direct sunlight. I had never seen this before. The blue glow was distinct and visible. Unable to believe my eyes I re-examined the certificate, it read: “no fluorescence”! I checked the stone myself, there was absolutely no fluorescence in either short or long-wave UV. How could this be?

Ian Balfour in his book, Famous Diamonds specifically mentions a “light blue tinge” as a characteristic of The 140 carat Regent Diamond. The Regent, originally called “The Pitt” was brought to England in 1670 and is, unquestionably, of Golconda origin (above left). Diamond scholar Herbert Tillander describes this affect as a “blue afterglow.” and notes that most Type II diamonds do not fluoresce. One exception, the Hope Diamond, a Type IIb (contains Boron) will not only fluoresce it will actually phosphoresce meaning that the stone will continue to glow last after the UV light source has been removed. Tillander further notes that some Type II diamonds have been found in South Africa’s Premier Mine, other sources mention Brazil.

Blue Haze:

Not all Type IIa diamonds exhibit this characteristic though Golconda stones do. I was able to examine another D-Flawless type IIa that placed side by side with the 9 carat, failed to exhibit the blue glow. In the Golconda stone, in direct sunlight, the blue hue floated above the gem like an early morning haze.

Fine Crystal; The 4th C:

Perhaps due to their pure carbon composition, Golconda diamonds exhibit another characteristic, a high degree of transparency, Balfour describes The Regent as having a “unique limpidity” that some dealers refer to as “super-d” or what I refer to in my book Secrets Of The Gem Trade, as a super-crystal. Very fine gems of all colors possess this characteristic. Compare a regular wine glass with one made of lead crystal, hold both up to the light and you will get the idea. When compared to another D color Type IIa not of Golconda origin, the difference was unmistakable. The characteristic strikes one as a combination of ultra-limpidity coupled with what connoisseurs refer to as “whiter than white” both characteristics were visible in the Golconda but not in the other gem.

The stone I examined was cut in a fashion almost identical to the Regent, a cut known as a baroque brilliant or old European (image left). Stones cut in this fashion are of a different character than the modern brilliant. The crown is higher and the pavilion facets are shorter and broader.

A fine diamond possesses two characteristics that define its beauty, brilliance and dispersion. Dispersion is the ability to break white light up into its constituent rainbow colors. In the single minded pursuit of maximum light return, modern brilliant cut gems have sacrificed dispersion to produce maximum brilliance. As a result they have become soul-less light return machines. A well cut baroque brilliant by contrast will exhibit a balance of brilliance and dispersion that gives the diamond its distinct character and beauty–a character that is missing in so many modern super-ideal cuts.

(image above, side view of Golconda diamond), Compare the color of the center with the side trillion that is definitely not of Golconda origin.

To summarize, there appear to be three visual characteristics that define the beauty of Golconda diamonds: A high degree of limpidity (crystal), an ultra-whiteness and a blue afterglow that appears in natural daylight. Golconda gems are Type IIa diamonds and this can be established by scientific testing. All Type IIa diamonds, however, are not Golconda diamonds; to be considered Golconda, they must possess the visual characteristics just described.

It is unclear whether Type IIa diamonds from other sources possess the characteristics discussed above, there certainly are some that do not. However, in the final analysis, we are interested in gems not geography. in gems beauty is the ultimate criterion. When it comes to Golconda diamonds if they deliver the goods, how much does source really matter.

If you are interested in learning more about Golconda Diamonds or are simply looking for a new way to dazzle your friends at cocktail parties. Read more about the four Cs of connoisseurship. Follow me on gem buying adventures in the pearl farms of Tahiti. Visit the gem fields of Australia and Brazil. 120 carefully selected photographs showing examples of the highest quality gems to educate the eye, including the Rockefeller Sapphire and many more of the world’s most famous gems. Consider my book: Secrets Of The Gem Trade, The Connoisseur’s Guide To Precious Gemstones.

“Wise is a renowned author… He’s
done a marvelous job of this first book, monumental work, a tour de force…My recommendation: Buy this book”.

Charles Lewton-Brain, Orchid

Only $37.95. Read a couple of chapters online: www.secretsofthegemtrade.com.

Buy it on Amazon: www.amazon.com

“Secrets of the Gem Trade” subject of Ventfort Hall lecture

– July 30, 2007

Described by Gemkey Magazine as “one of the world’s foremost gem connoisseurs,” gemologist Richard W. Wise will bring his expertise to a Ventfort Hall Mansion and Gilded Age Museum visual presentation on Wednesday, August 29 at 4 p.m. A Victorian Tea will follow this final lecture of Ventfort Hall’s summer series.

Admission for the lecture and tea is $15 per person, members $12. For more information or reservations, please call 413-637-3206. Ventfort Hall is located at 104 Walker Street in Lenox.

Color Change/Color Shift

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Gem Collecting for Fun and Profit

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Collector’s Corner; How and What to Buy

Everybody wants a steal, ‘er, deal:

I get a lot of emails from my readers with various questions. Friday I got a call from Diane, she read the book and wanted to know what stones a budding collector should be looking at. Now, when most people ask me that question what they really mean to ask is “what is available and cheap.” Why not, everybody wants a deal. Thing is in gemstones there are two kinds of deals.

As a collector you should be looking for the fine and the rare. Fact is, in gemstones just about everything that is fine is, in fact, rare, the finer it is the rarer. I like to use the example of amethyst. Amethyst is quartz which, geologists tell us makes up almost 26% of the earth’s total bulk. So quartz isn’t particularly rare but, a beautiful transparent deep purple quartz that exhibits red scintillation in incandescent light is extremely rare. (Image above: #6999: 15.06 carat custom cut Deep Siberian Amethyst)

You can buy amethyst for between $1.00-100.00 per carat, quite a price spread but you will probably pay $50-100 per carat for a #1 color “deep Siberian” amethyst described above depending upon size, clarity, crystal and cut. You can buy #2 color, a beautiful deep purple amethyst that does not exhibit the requisite red flash for maybe $20-$35 per carat. Given the fact that #1 color is hundreds of times rarer and perhaps three times the price, you figure it out.

What’s hot, what’s not:

In Secrets Of The Gem Trade I write about something that might be called the Gemstone Market Price Cycle or (GMPC) (love those acronyms) The cycle works like this: When a new gem or a new source of an existing gemstone is found, the new material floods into the market increasing availability and decreasing price. Gems, other than diamonds, normally occur in fairly small pockets so the flood doesn’t last long. What does happen is the increased availability stimulates interest which translates into market demand. As demand increases the material begins to run out and as supply decreases, prices increase. By the time the dust clears the market price is higher than before the new material was found. (Image above: #6064: 6.93 carat Nigerian Spessartite Garnet)

Recently we have seen this happen with several gemstones. Consider spessartite garnet, the 4th most brilliant gemstone. A decade ago, most jewelers had never seen a spessartite never mind the hot tangerine orange gems available in the market today. Most fine spessartite came from one source; The Little Three Mine in Ramona California. This material was extremely rare in the marketplace and sold for fairly high prices. One knowledgeable dealer told me that the total production from Little Three was probably on the order of 10,000 carats. There was simply not enough spessartite to make a market which gives rise to the paradox that if its so rare that no one knows about it, there is no demand. (Image right:#8084: 9.51 carat Nigerian Spessartite Garnet)

Enter the Nigerian find: All of a sudden there are Nigerian dealers all over Tucson with plastic bags full of juicy fruit orange rough. There is high quality spessartite everywhere and was it cheap. I remember selling 5+ carat extra-fine pure tangerine orange gems to collectors for $275-300 per carat. In the six years or so since the Nigerian strike the GMPC has played out; demand has increased, supply has decreased and prices have doubled. Prices now are higher then they were before the strike when the stone was a good deal rarer.

Of course this all took place BGT, Before 24 hour Gemstone Television really took hold back in the good old days when the free market was still alive and well. No one successfully had cornered any gem deposit and there was little if any hype to distort natural market forces. The effect of the shopping channels can be gauged by looking at Andesine, a form of sunstone that has become the darling of gemstone TV and is being sold by the shovel full to the unsuspecting at ridiculous prices.

Strategic Collecting:

So what’s a collector to do? Fact is the GMPC is still valid so long as y’all keep a jaundiced eye on gem TV. Two stones, spessartite and Peridot, particularly the material from Pakistan that began to trickle into the market in 1995 are still on the downside of the cycle, and, in my opinion, available in fine quality at reasonable prices. As for Spessartite, buy the high grade light-medium tone (30-40%) pure vivid orange to cinnamon orange. Remember once you go beyond medium tone, orange becomes brown and that is to be avoided.

Pakistan Peridot:

At its best, material from this source sports a medium grassy green primary hue. The best will read as as a strong medium toned green with just a touch of yellow and beware the gray mask. Pakistan Peridot will stand toe to toe with the best Burmese and is far superior in both size and color to the stones from the traditional Arizona source. Stones are eye-flawless and readily available in 5-10 carat and even larger sizes. (Image above: #7033: 8.09 carat Custom cut Pakistan peridot)

The rough material is getting scarcer and there is upward pressure on prices which are beginning to be felt in cut gemstone market. Peridot also has built in demand, it is also the traditional August birthstone. Every summer I have August babies come into my gallery, see cut stones from this source and fall in love.

My recomme
ndation: buy Spessartite and Peridot and buy only the best. And, just three words of caution to those of you who think that you that you can steal a fine gemstone on Thai websites, Fleabay or Gem TV, get over it! I recall one client, I think he was a Dentist, after I told him a story of one of my trips to Burma asked me, “but do they know what they have?” The Burmese have been digging ruby since the Bronze Age. Gems are one of the world’s oldest articles of trade. Fine gems made their way from Afghanistan to to ancient Sumer as early as 2000 B.C. With all that history, do you really believe these folks haven’t figured it out? Take my advice: If it sounds like too good to be true, it is too good to be true!

Book Review

Extra-Lapis #10: Opal, The Phenomenal Gemstone

by Richard W. Wise
© 2007

It just arrived, my latest Extra-Lapis, this one #10 entitled; Opal, The Phenomenal Gemstone. For those of you who don’t know, Lithographie, LLC of East Hampton, Connecticut www.lithographie.org. publishes an English version of the famous German gem/mineral magazine Extra-Lapis. In the past few years monographs in this series have focused on gold, tourmaline and emerald along with numbers dedicated to important gem/mineral locations such as Madagascar and Pakistan and occasional forays in to mineral kingdom with issues on fluorite and calcite.

Extra-Lapis #10 is the latest word on opal. It includes articles on all the current producing areas as well as historically important locations both major and minor. The latest theories on what causes those tiny little silica spheres that create play-of-color to do the thing they do and much more.

Great writers too: The great husband and wife writing team Si and Ann Fraser kick the issue off with an overview of opal’s history as a gemstone. Much of this information is old hat but well organized and presented and include the intriguing assertion that Mexican opal was certainly known and valued by the Mayans and Aztecs and that, despite Pliny’s famous description, opal may not have been known by the Romans at all. In other articles; Veteran dealer Andrew Cody provides an overview of sources in South Australia, Elizabeth Smith, author of Black Opal Fossils of Lightning Ridge contributed an excellent piece on current conditions and mining at “The Ridge” including a scrumptious photo essay on black opal nobbies.

Other articles provide beautifully illustrated history and updates on diverse sources such as Slovakia, White Cliffs, Queensland, Virgin Valley, Honduras and Ethiopia. There is a map of worldwide opal locations, an interesting but incomplete glossary of opal terms. What is missing is a good bibliography and a solid discussion of opal classification and quality grading.

This latest 112 page offering is, like all the others, beautifully made and wonderfully illustrated. The editors go to great expense: Each softbound issue is printed on heavy chrome coat, printing and image reproduction is of the highest possible quality.

Extra-Lapis #10 is highly recommended to anyone interested in gemstones and is a must have for opal enthusiasts. The price is for #10 is $30.00 for a single issue but if you will take my advice buy a four issue subscription for $90.00.

Interested in reading more about real life adventures and secrets of the gem trade? Follow me on gem buying adventures in the exotic entrepots of Burma and East Africa. Visit the gem fields of Austrailia and Brazil. 120 photographs including some of the world’s most famous gems. Consider my book: Secrets Of The Gem Trade, The Connoisseur’s Guide To Precious Gemstones.

“Wise is a renowned author… He’s
done a marvelous job of this first book, monumental work, a tour de force…My recommendation: Buy this book”.

Charles Lewton-Brain, Orchid

Only $39.95. You can read a couple of chapters online: www.secretsofthegemtrade.com.

Buy it on Amazon: www.amazon.com

Rocky Road II; Grading The Colorful

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Rocky Road II; Grading The Colorful

By Richard W. Wise, G.G.

Mirror, mirror, on the wall, who will be the biggest of them all? An Interview with Michael Haynes

After several near misses last Saturday I spent a bit of quality phone time with Michael Haynes, President of Collector’s Universe (CU). First a little background: You will recall from Part I that CU has acquired American Gemological Laboratory (AGL) the only major gem laboratory that quality grades colorful gemstones. The acquisition that took place in early 2006, with a 3.5 Million upfront payment to AGL President C. R. Beasley with an additional 3.5 million payable in five years.

Collectors Universe is a public company traded on NASDAQ with a market capitalization of 120 million dollars. The company bills itself as “the leading provider of value added authentication and grading services of high-value assets”. According to Haynes; last year CU certified 1.8 billion dollars worth of collectables including 65% of all stamps certifed, 85% of sports cards and perhaps 45% of all coins.

AGL is CU’s third acquisition on the road towards its publicly stated objective of becoming the major purveyor of gemstone quality reports “maybe not tomorrow, or next year, but within the foreseeable future. As part of its strategy CU had previously acquired GCAL a diamond grading laboratory and Gemprint the company that has patented a method of taking an identifiable “fingerprint” of a cut diamond.

Michael Haynes is a passionate pitchman. He sees CU’s coming dominance of the certification business as a win-win for everyone. Why he asks isn’t the fine gemstone business experiencing similar growth levels as other luxury products? According to CU’s president, it’s a matter of consumer confidence or the lack thereof. He contrasts the experience of buying a Hermes scarf with that of buying a ruby necklace. You go to a Hermes store. There is no question of authenticity or value; it is only a question of price. You go to the jewelry store and you enter a world of doubt. Is it real? What is it really worth? “Money”, says Haynes, “travels the path of least resistance.” Buying an expensive piece of jewelry, all you have to rely on is the seller and he is after all the seller. Independent third party certification by a publicly traded company will end the doubt and level the playing field, Haynes puts it succinctly: “remove doubt, increase sales”.

As any professional will attest, much of what Haynes says is spot on. Consumer doubt is a component of a large majority of missed sales opportunities particularly high-end sales. Doubt coupled with professional ignorance and competitive low-balling have made gem and jewelry selling a competitive mine field (read: my blog post: Getting an Appraisal; Some Do’s and Don’ts.)

Next I asked Haynes how he foresees CU succeeding where so many have failed? “By establishing an promoting a consistent standard.”

How about competition from GIA? Haynes barely skips a beat. “That’s a question”, he suggests, “you should be asking GIA”. With CU’s triumvirate of acquisitions Haynes appears confident that CU has covered all the bases. If the Gemological Institute of America wishes to compete in colored stone grading game, it is GIA that will be playing catch-up.

Laboratory One-upmanship:

At the season opener, Tucson 07, CU will throw out the first ball of the season. Its AGL subsidiary will announce a plan to offer a range of gem certificates. From being one of the most expensive labs, AGL is about to become the least expensive offering a range of modestly priced grading reports. In a separate conversation last week, AGL President Cap Beasley outlined the new program. The Lab will offer certification on a series of levels called Fast Track. For $25, Fast Track I will offer a credit card sized report providing just authentication and enhancement. Fast Track II will add the 4 C’s for $50 and for $75 Fast Track Premier will add type as in Burma-type, Paraiba-type, etc.

Collectors Universe is aiming at the consumer. The aim is to produce a document that is easily understood by the retail buyer. Perhaps this new format will accomplish that. AGL’s current offerings are not all that easy to understand. Though in recent years the lab has added a Total Quality Integration Rating (TQIR) to summarize all of the various grading factors and give the gem an overall quality grade.

Book Review

The Sancy Blood Diamond

In this historical potboiler, author Susan Ronald traces the history of the Sancy Diamond from the mines of Golconda to its current tranquil resting place in The Louvre. As the largest and most famous diamond in Europe from the Fourteenth through the Seventeenth Century, The Sancy had many admirers and several owners; from Charles the Bold through Napoleon, kings, queens, cardinals and dukes, some of them major players on the stage of European history.

Ronald does more; she is a knowledgeable political-historian and along the way she weaves the Sancy’s chronology into to woof and weft of European political history.

As Ronald shows, The Sancy and by extension other famous gems did more than add luster to the crowns of European Monarchs. Goldsmiths were Europe’s first bankers. It should come as no surprise, therefore, that long before the present conflicts in Africa, large and famous gems provided the bloody collateral of choice, pledged by Europe’s crowned heads to the financiers who bankrolled Europe’s major conflicts.

Ronald’s account is authoritative, fast paced and reads like a Machiavellian analysis of history. From the killing fields of Nancy, to Charles I’s beheading, to the court of the Sun King, Ronald shows how sex, power and greed as represented by The Sancy, fueled the politics of Europe. The book was published in 1995, don’t know how I missed it. The book is particularly relevant given the present interest in conflict diamonds. Highly recommended. For more on the stone and the author: www.thesancydiamond.com

Ronald, Susan, The Sancy Blood Diamond, Wiley & Sons, New York, (hardcover) $27.95, $18.45 on Amazon.

Into Africa:

For the first time in twenty years I will miss the Tucson Gem Shows. I will be in Brazil and cruising the coast of West, South and East Africa until mid-February. Meanwhile the contest goes on. (see the previous post, Rocky Road I) Guess the value of the French Blue diamond in 1698 and win a free copy of my book, Secrets Of The Gem Trade, The Connoisseur’s Guide To Precious Gemstones. The Secrets website will also not be functioning for orders. If you need it right away order it on www.Amazon.com. (See below)

Interested in reading more about real life adventures in the gem trade? Follow me on gem buying adventures in the exotic entrepots of Burma and East Africa. Visit the gem fields of Austrailia and Brazil. 120 photographs including some of the world’s most famous gems. Consider my book: Secrets Of The Gem Trade, The Connoisseur’s Guide To Precious Gemstones. Now only $26.95. You can read a couple of chapters and order online: www.secretsofthegemtrade.com.

Buy it on Amazon: www.amazon.com

Grading The Colorful

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Grading the Colorful, The Rocky Road to Quality Assessment

by Richard W. Wise, G.G.

“Collectors Universe has stated it has every intention of becoming the world’s leading purveyor of diamond and colored stone pedigrees—”maybe not tomorrow, or next year,” (CU President) Haynes says, “but within the foreseeable future.”

David Federman, Professional Jeweler, 2006

At the beginning of a new year it is traditional to assess the past year, make resolutions and talk about the future. Several happenings over the past twelve months that considered in isolation are important taken as a whole appear to be crucial milestones along the road toward colored gemstone quality grading.

A consortium of seven major gem laboratories under the aegis of the Laboratory Manual Harmonization Committee (LMHC) established important precedents:

First, they abandoned the traditional protocol of naming a gem based on species and variety. The committee agreed that on grading reports issued by member labs to use the term “Paraiba” to describe all copper colored or cuprian tourmalines regardless of their actual source.

In a separate decision, the LMHC also decided to stray beyond the realm of verifiable science and enter the world of aesthetics. They agreed to adopt a set of color parameters for and use the term “Padparadscha” sapphire on grading reports issued by member labs.

This year a new player entered the grading games: Collectors Universe (CU), a publicly traded company that provides certification for coins stamps and guess what, baseball cards purchased American Gemological Laboratories (AGL) the only major U. S. lab that issues quality grading reports on colored gemstones. CU has the financial muscle and appears poised for an strategic play: The company already owns Gem Certification and Assurance Lab (GCAL) as well as Gemprint, the diamond identification and registration system that will laser print an ID # on gemstones.

In order to have a universal colored stone grading system you must have a universally acceptable methodology. Internet shoppers, in particular, are demanding a way to compare apples to apples and what the market requires the market sooner of later gets. Getting all major players to accept a single methodology may be difficult but a broad basis of agreement between a number of important labs may do the trick. The LMHC includes seven of the world’s most respected gemological laboratories: (AGTA Gem Testing Center, CISGEM (Milan), GAAJ (Japan), GIA (USA), Gemological Institute of Thailand, Gübelin Gem Lab (Switzerland) and SSEF Swiss Gemmological Institute (Switzerland) missing only AGL and The Swiss Lab Bangkok (GRS) the very well respected Bangkok based lab run by Adolph Piretti.

Historically, no institution, not even the mighty Gemological Institute of America (GIA), the originator of the universally accepted diamond grading system, has succeeded in creating an acceptable colored stone grading system. GIA tried twice, first in the 80s Colormaster, a sort of color blender and then with Gemset, a set of round faceted plastic doohickeys, both of which were flawed and failed to win industry wide acceptance. GIA has wisely abandoned its go it alone strategy and joined LMHC.

Instrument based color determination appears to be the wave of the future. According to American Gemological Laboratories C. R. “Cap” Beasley “instrument based measurement is simply more consistent”. The fact is; you have the rock, the light and the observer, standardize the latter two and you are eliminate two variables. Does Beasley have an instrument? None that he will admit to.

AGL is still the only major laboratory that grades colored gemstones. Beasley introduced his own system, Colorscan, in the early 1980s, a system that many gemologists including this writer believes was the most viable system yet created. Colorscan, however, relied on the human eye as observer. New Computer based systems such as Gem-e-Square that project a range of hue/saturation/tone on a color computer monitor also require the human eye and judgment to make a call.

Collectors Universe appears to be making a bid to become a major player in quality grading. I will be interviewing CU president Bill Haynes, later in the week. Stay tuned.

Interested in reading more about real life adventures in the gem trade?

Follow me on gem buying adventures in the exotic entrepots of Burma and East Africa. Visit the gem fields of Austrailia and Brazil. 120 photographs including some of the world’s most famous gems. Consider my book: Secrets Of The Gem Trade, The Connoisseur’s Guide To Precious Gemstones. Now only $26.95. You can read a couple of chapters and order online: www.secretsofthegemtrade.com

Do ya feel lucky? Win A Free Copy:

Thats right win a free copy of Secrets Of The Gem Trade, The Connoisseur’s Guide To Precious Gemstones, answer the question.

The Hope Diamond, Inflation in the Seventeenth Century

In 1669 Louis XIV of France purchased the French Blue diamond from the famous gem merchant Jean-Baptiste Tavernier for 220,000 livres or 42.7 million dollars (1 livre = $1,941.). In an inventory taken by the French crown in 1691 the Sancy Diamond, a colorless stone of 55.23 carats and the largest white diamond in Europe at that time, was valued at 24.2 million dollars.

By the time this inventory was taken, The French Blue, had been recut by M. Pitau to 69 carats, a 40% loss in weight. Despite this the stone that ultimately became the Hope Diamond, was valued at…in 1691? The first person who comes closest wins a signed paperback copy of Secrets Of The Gem Trade. Post your answer in French livres and your email address to the Comments section of the blog. Winner’s name to be posted on GemWise in two weeks. Hint: read Ronald, The Sancy Blood Diamond, Morel, The French Crown Jewels

Lighting and Grading Gemstones Part II

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LIGHT UP YOUR LIFE

by Richard W. Wise, G.G.
© 2006

What is the best lighting environment to view gemstones? In part I of this post I discussed the various lighting options and the pros and cons of each. In part II I will write about the lighting some of the world’s foremost gem experts and connoisseurs choose to both view and evaluate gemstones.

Among the experts opinions differ somewhat as to which “daylight” Kelvin temperature is best but each accepts daylight as the standard. Stephen Hofer one of the world’s most respected authorities on colored diamonds, maintains that 5500K works best for colored stones and 6500K is best for diamonds both white and colored. In his lab, which is dedicated to the evaluation of fancy color diamonds, all grading work is done under 6500 Kelvin fluorescents. C. R. Beesley, President of American Gem Labs in New York, prefers Vitalite a bulb manufactured by The Duro-Test Corporation with a Kelvin rating of 5500. “Most people don’t do their homework”, says Beesley, “comparing color temperature isn’t enough…” Beesley tested more than twenty different light sources in the process of developing his Colorscan colored stone grading system to gauge their actual effect on gemstones.

In 1994 GIA completely revamped its color grading system for colored diamonds, shifting from Veralux, a so-called low UV lamp rated at 6200K, (see Secrets Of The Gem Trade, p.60, fn) which remains its standard for grading colorless diamonds to a 6500K average daylight fluorescent bulb for grading colored diamonds. The lamp is manufactured by Kollmorgen Corporation. GIA also uses a 6500K for general research purposes. The Institutes use of light of this Kelvin temperature is in no way an endorsement of the use of this type of lighting by jewelers. According to James Shigley, GIA’s Director of Research, 6500 was chosen because it is a recognized standard used by color scientists. Little or no thought was given to enhancing the beauty of gemstones.

Incandescent and quartz halogen lamps can be made to resemble daylight with the addition of a blue filter. Duro-Test currently markets a “super-white halogen” that does the same job. I conducted a series of experiments with the Duro-Test product and found that this type of lighting does wonderful things for blue sapphire, aquamarine and amethyst, but does nothing to reduce the muddy look in blue and green tourmaline. “Super-white” induces a distinctly overblue look in rubies and tanzanite takes on an odd blue/violet multi-color effect quite dissimilar to its appearance in any other lighting environment. In diamond, “super-white” overly enhances the yellow/blue luster of the stone.

The problem!, filtered light makes for unintended results. Unfiltered fluorescent lighting can exhibit a relatively balanced spectrum when graphed on what scientists call a “Relative spectral power distribution” curve. Filtered lamps show spikes in this curve which are areas of color deficiency.

Another type of lighting called Neodymium is currently being marketed as a “full spectrum incandescent”. According to Roger Schoenfeld, a lighting specialist with Durotest, this is really a standard yellowish incandescent incased in a special glass invented in Sweden, which reduces yellow and generates a spectrum richer in red and blue. Neodymium is not a bad choice. It is excellent for diamonds. Neodymium is a bit better than standard quartz for sapphire and aquamarine though not as good as “super-white”. All three sources suppress the violetish to purplish secondary hue of the finer grades of sapphire.

Compared to daylight, neodymium works well with ruby, amethyst, emerald and tsavorite garnet. It is no worse with blue and green tourmaline which seems to be a true day stone, i.e. it looks its best in daylight and in daylight fluorescent 5000-6000K. Pink & red tourmalines do fine in Neodymium “full spectrum”, it does not produce the brownish secondary hue that most pinks exhibit in standard incandescent but, rather makes them look violetish. Tanzanite looks about the same as with quartz light; bluer than stan
dard incandescent and without the otherworldly quality of “super-white”.

Three or four years ago, Tailored Lighting introduced a 4700 Kelvin MR-16 lamp which has the highest Kelvin temperature of any incandescent bulb and may be the best solution yet for interior lighting. The new Solux lamp uses a new type of reflector to boost the quartz halogen lamp into the daylight range. This technology produces lighting with a fairly even power distribution curve (CRI) that shows no spikes in either the red or blue areas of the visible spectrum.

In a short, down and dirty test, Solux worked well with tourmaline, reducing the muddiness produced by all other incandescent light sources. Sapphire and ruby also benefited from this type of lamp, showing they’re colors in true daylight fashion. Solux also improved the diaphaneity of tanzanite. On the down side, Solux appeared to add a gray component to aquamarine and pink topaz which reduced the saturation and flattened the color.

Changing lighting environments have always been a problem for both buyers and sellers. You buy in one light, sell in another. Traditionally dealers who do extensive buying outside their offices have relied upon comparison stones, stones of well known color, which they carry or wear on buying trips.

I use two fixtures with twin four foot fluorescent lamps to give an overall daylight environment combined with several of the new Solux MR-16 4800K quartz halogen lamps in my own laboratory which doubles as a salesroom and consider this combination to be the closest possible to a true daylight environment. I use Duro-Test Vitalite in one fixture and Kollmorgen 6500K average daylight in the other. The use of the 6500K is to compensate for the 4800K Solux, to kick up the Kelvin temperature of the overall environment towards 5500K.

The combination of of daylight fluorescent with Solux works acceptably across the spectrum of gemstone colors. The fluorescents create an overall daylight environment and the Solux MR-16 provides the punch. This lighting temperature gives a balanced daylight color rendering when compared to New England north daylight. Several years ago, a German firm, System Eikhorst, introduced a lighting system based, in part, upon my recommendations. It includes both daylight fluorescent and Solux fixtures.

When making a purchasing decision it is important to identify the light source you are viewing the stone and to view the stone in as many lighting environments as can be found. Regardless of my geographic location at the time, I always compare each stone in daylight and 3200K incandescent to see how the stone reacts at both ends of the lighting spectrum.

If a consistent workable colored stone evaluation system is ever created, the lighting environment will of necessity be standardized. To achieve reproducible results, there are three variables; the observer, the gem observed and the lighting environment. The standardization of the lighting environment will remove one variable. This leaves one remaining variable, the observer. Either we must accept some nuances of subjectivity or build a gem grading robot replace to connoisseur’s eye and dictate our taste.

Light Up Your Life; Lighting and Grading Gemstones, Part I

1 Reply

LIGHT UP YOUR LIFE

Lighting and Grading Gemstones Part I

©2006

Richard W. Wise, G.G.

It used to be so simple, the brighter the light the better the light. You had the light from a fire and the light from the sun, that was it. In those good old days it was easy to figure out watt was watt! Today we have a myriad of options, “warm light”, “cool light”, “daylight.” Gem dealers are beginning to discover that the lights that make his rubies look like a pigeon’s blood may make his tourmaline look like a dog’s poop. As for the buyer, caveat emptor baby, check the bulb!

We are all familiar with the daylight standard: diamonds and colored gemstones are supposed to be judged in north daylight. Why?, because north daylight, specifically north daylight at noon is white light balanced between the red and blue spectrum. Sounds simple, but wait a moment! Dealers have long realized that the quality of daylight differs in locations throughout the world. North daylight at noon in Bangkok is qualitatively different from north daylight in New York.

The quality of natural daylight is affected by several factors, including latitude and air quality. In addition, the relative strength and color composition of daylight changes as the day progresses. “Don’t buy blue sapphire after 2:00pm“. That was the advice my Bangkok broker gave me on my first trip to Thailand. This dealer’s truism teaches a basic fact that as the day progresses the color composition of sunlight moves from yellowish into the blue range then toward red at sundown.

Color scientists measure color as a function of light temperature and express it in units called Kelvin (K). a light filament heated red will have a Kelvin temperature of 1000-1500K, orange like a candle flame has a color temperature of 1500-2500K, yellow between 2500-4000K, white as in daylight is defined as a range; 4000-10,000K. In practice, increasing Kelvin temperature reduces yellow and adds blue.

If we wish to get a true color rendering using the daylight standard we will want a bulb that produces average noon sunlight with its relatively balanced color spectrum with a color temperature between 5500-6500 Kelvin. Unfortunately, the Kelvin temperature of an incandescent lamp falls between 3000-3200. The new low-volt quartz halogens have a color temperature of only about 3200K. Light in this temperature range is distinctly yellowish and will enhance the look of stones in the yellow, orange and red range. It will add an attractive bluish hue to chromium-vanadium colored gemstones like emerald, chrome tourmaline and tsavorite garnet. However, some Emerald, particularly Zambian emerald, can look distinctly overblue in this type lighting and 3000k light tends to muddy the crystal (reduce the transparency) of iron colored green and blue stones such as tourmaline and sapphire.

Daylight equivalent lighting does exist in fluorescents but not in incandescent single point spot and flood lighting that is used by most dealers and jewelers to bring out the brilliance of a gemstone. Daylight fluorescent bulbs with Kelvin temperatures between 5500-6500 are available. These lamps are marketed, usually as “daylight” lighting by several companies under various trade names. Unfortunately fluorescent lamps generate a diffused light and produce insufficient punch, what scientists call lumens, to bring out the best sparkle in your gems. To further complicate matters, there is no recognized international standard for a daylight bulb. Each manufacturer decides for himself what to consider “daylight”.

Coming next: Part Two, Learn what types of lighting the experts favor, Stay tuned…

So, you want to learn more about lighting and judging gemstones? Read the book:

“Secrets Of The Gem Trade is very highly recommended to anyone interested in gemology as a superbly organized, authoritative, comprehensive, and easy-to-follow reference.”
Midwest Book Review
April 2006