Category Archives: grading and pricing Columbian emerald

Gem Grading: The Death of the Lightbulb and Other Brilliant Ideas

Color temperatures a various types of lighting. 5500-6500 is the Kelvin temperature of daylight. GIA uses a 6200 Kelvin light source for diamond grading.

New Technologies May Require Changes is How We Look At Gems:

In 2007 amid little fanfare, Congress passed a law that required that the efficiency of that iconic household standby, the incandescent light bulb, be improved or perhaps accept its doom. The bulb has been around a long time and the technology has remained virtually unchanged since it was invented by Thomas Edison in 1881. Turns out the old bulb is a real energy waster, only 10% of the energy used is given off as light, the rest is dissipated as heat. Though some called it the death of the incandescent light bulb, Congress merely dictated an increase in efficiency, 20% by 2014, 60% by 2020.

Though the efficiency standards do not state what is allowed, such a dramatic increase in efficiency is bound to require new technologies which are likely to mean changes in the light spectrum produced by whatever technology replaces the old standard. No one has given much thought to the consequences this will have in the gem trade. The new standards are scheduled to take effect this January.

In the evaluation of quality, gemstones have been traditionally viewed under two light sources, noon daylight or more lately daylight equivalent fluorescent lighting and plain old incandescent (in the 19th Century it was candlelight). A stone that looked good by day but muddied up under the lightbulb is taken to be inferior to one that holds its color in both lighting environments. In 2003 I published a book, Secrets Of The Gem Trade, that divides gems into daystones and nightstones. The terms refer to gem varieties that look best under a given source. This seemingly bright idea may mean dramatic reductions in oil imports, but wait! What about the gem business, what’s a connoisseur to do?

The Tea Party To the Rescue:

Well our worries may be over, just last week the House passed legislation to deny funding to the law. Apparently the bill’s original Republican sponsor, Texas Representative Michael C. Burgess had an epiphany. He has seen the, ah, light. “The government has no right to tell me or any other citizen what type of bulb to use at home,” no matter how much energy it might save says Mr. Burgess. We have the right to waste all the energy we like in the privacy of our own bedrooms, says so in the scriptures.

But seriously folks! Sooner or later, new, more efficient types of lighting are bound to replace the old standby. Will there be a new standby? Probably not. We are pretty much at the point where the type of lighting used will be dictated by the setting that it is used in. Call it dial a light! At that point will gem grading light be standardized. To some degree it already has. Most laboratories use some artificial version of daylight. The Gemological Institute of America (GIA-GTL) uses a 6200 fluorescent bulb, American Gemological Labs uses a 5500 Kelvin bulb. What is the next step? Stay tuned to GemWise.

Book Review: The Colour of Paradise, The Emerald In The Age of Gunpowder Empires

Kris Lane

The Colour of Paradise, The Emerald In The Age of Gunpowder Empires

280 pages including appendices

ISBN: 978-0-300-16131-1

The history of the gem trade is a difficult research topic because gemstones are very small objects of great value that have been highly sought after for millenia by rich and powerful people looking for wealth that was portable and easily concealed. The trade itself has been controlled for centuries by minority groups, often oppressed minorities, Jews, Armenians and Indians for whom secrecy was a proven form of self preservation. Kris Lane is a historian, a Professor of History at the College of William and Mary. In The Colour of Paradise, Professor Lane focuses very well honed research skills on the history of the emerald, one of the rarest, most mysterious and highly valued of all gemstones.

The book contains no particularly major revelations. Most historians of the trade are aware that India’s so-called “old mine” emeralds were, in fact, Colombian emeralds imported by the Spanish into India in the Sixteenth and Seventeenth Centuries. Lane’s contribution is to meticulously document both the early history of Spain’s brutal exploitation of Colombia’s indigenous people and its gem wealth. He gives us a well documented overview of early trade routes and uncovers some very interesting and original information concerning 16th Century production; methods and emerald values.

Lane begins with the 16th Century and follows emerald production in Colombia right up to the present, with a good account of politics and production into the 1990s.

All and all this well organized and well written account brings real clarity to a relatively murky area of history. The book also contains detailed appendices estimating early emerald at Muzo, relative values of emerald and diamond in Europe in the 17th Century and an extensive bibliography. The author has uncovered several original accounts that have until now been unrecognized. Highly recommended.

Investing in Gemstones, Part II; A Strategy:

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Avoiding the Con:

There were a number of phony gemstone investment schemes in operation during the hard asset investment craze of the late 1970s and early 1980s. Until Congress put a stop to it, investors were purchasing, gems, antiques and Shaker rocking chairs as part of their IRA portfolios.

To avoid prosecution many gem investment scammers set up boiler room operations in Canada, but sold mostly to gullible U. S. investors. The pitch was simple and ingenious. To keep buyers from seeking an outside appraisal, the gems arrived in sealed packets with a microfilmed “certificate of authenticity”. Buyers were warned that breaking the seal would invalidate the certificate and negate affect potential resale.

Over the years, several victims have sought me out to appraise their purchases. In all cases, the gems were wildly overpriced stones and of a quality best described as Continue reading →

Rough Roulette; Colombian Emerald Part II

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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”.

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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.”

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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.

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Emeralds; The God's Shed Green Tears

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The Emerald of Colombia Part I

By Richard W. Wise, G.G.

Green Gold:

There they sat, scattered like match sticks across the white desk blotter, glowing a rich cool green in the late afternoon sun. My breath catches in my throat. I do my best to maintain my cool, to politely keep my eyes on those of my host, a suave youngish Colombian businessman in a white dress shirt, the jacket of an expensive pin-striped suit thrown over the back of his desk chair. “Youngish” is, of course, a relative term when you’re pushing 63. The dealer smiles and motions me to a seat and there they were right in front of me, a king’s ransom of emerald crystals. I try not to dwell on the four tough looking guys with the semi-automatic rifle in the room we passed though on the way into the office. They too wore nice suits.

This was a sight I never expected to see. I have traveled all over the world and seen a number of exceptional gemstones but never have I seen a rough parcel of such high quality of anything, anywhere, never mind gem emerald. I pick up one crystal, it is a bit distorted in form but it is clean and the size of my thumb. I hold it up to the light. Completely clean a medium dark slightly bluish green. I do notice an interesting pattern of zoning, several thin dark lines, almost black, that run perpendicular to the length of the crystal.

“That one cost me $35,000”, the dealer volunteers.

“How much does it weigh”, I ask.

He places the crystal on a scale. I do a quick calculation. The price comes to $1, 411.00 per carat.

The dealer, perhaps regretting his candor with the inquisitive American author, hastens to add that the average yield in cut stones is only about 25%.

Point taken!, that means the average cost of the parcel after cutting works out to $5,644.00 per carat. This is beginning to sound like a multi-million dollar crap shoot because, as we are about to witness, this parcel contains a range of qualities.

Columbia’s Top Cutter:

Senor Adolpho Argotty is considered Columbia’s top emerald cutter. Now 55 he began cutting when he was 15 years old. His father wanted to be a cutter but was not very good at it. Argotty laughs, “so he became a teacher.”

We have been invited to watch Senor Argotty cut two rough crystals from the big La Pita parcel; one weighs 7.17 carats the other 8.53 carats. Argotty works by hand, literally! After examining the two crystals for a few minutes he takes one and casually puts it to the wheel. I see no scales, no calipers, no jam-peg, no measuring devices of any kind, not even a ruler.

The first step is called pre-forming; it is the most important step and requires the highest degree of skill. The wheel is charged with diamond grit mixed with water. The pre-former decides what to keep and what to cut out and that determines the shape and weight of the finished gem. The facets will be added later.

Next: Argotty puts it to the wheel! Stay tuned.