Category Archives: gem labs

Kashmir Sapphire, Another Auction Record

Dateline: Hong Kong

Current world record holder, 26.41 Carat Kashmir Sapphire Courtesy: Christie's

A New World’s Record:

November 29th, Christie’s Auction House, Hong Kong, sold a 26.41 carat Kashmir sapphire for 3,838,508 or $145,342.00 per carat. This sale establishes a new world’s record price of Kashmir sapphires sold at auction, besting the former world’s record also established at Christie’s (New York) for the 22.66 carat Hill Sapphire which sold in April 2007 for $3,064,000 or $135.216.00 per carat.

Kashmir sapphires were originally found on a small hillock 13,000 feet up in the mountains of the now disputed Indian state of Kashmir in 1881-1882. The harsh conditions at this altitude meant that the mines could only be worked about one month per year. By 1887 the output of the mines had diminished substantially. The original lessee abandoned the diggings in 1905. Four other groups had a go at it with little success and the sites were more or less abandoned in 1928. A bit of material is still occasionally found, alluvial material at the bottom of the ridge, but the major production of Kashmir sapphire lasted a mere six years.

Kashmir stones are highly esteemed for their color, a vivid purplish blue, a hue often described as “cornflower blue.” Others, most notably Richard W. Hughes, author of the seminal book Ruby and Sapphire, describe the finest color as a Pepto Bismol bottle blue. The problem with this characterization is that Pepto Bismol bottles are now pink—but there are those of us who are old enough to recall when the bottles were a bright medium blue. I recall seeing only one stone of this description and it hailed from Sri Lanka.

Kashmir’s famous characteristic, however, is the silky, milky or fuzzy texture that somewhat diminishes the diaphanity (crystal) of the stone. Myriads of tiny inclusions that resemble dust caught in a ray of sunlight or a sub-microscopic milky way, will, when present, diffract and refract the light, causing the stone to take on a velvety glow. Similar inclusions are sometimes found in gems from Madagascar and Sri Lanka, but absent geographical certainty, these “Kashmir type” sapphires do not command nearly the price of those with old mine provenance. The current record holder was accompanied by four laboratory reports certifying Kashmir origin. This, of course, begs the question: If gems are all about beauty and sapphires from other locations have all the characteristics of the finest Kashmir, why does anyone care where the stone is from? The short answer is branding. The market recognizes a value in stones from the original mine. It is also fair to say that although stones can be found with the characteristic glow, very, very few approach the pinnacle of Kashmir color. I have only seen two stones that can be described as #1 Kashmir color and both were from the old mine.

What a difference a light makes, record breaking sapphire before re-cut, note the large culet visible through the table. Photo courtesy Stone Group Labs.

What a difference a light makes; the current record holder before a re-cut shaved a single carat. Note the large culet visible through the table and the characteristically velvety texture or crystal. Photo courtesy Stone Group Labs.

Rapidly Escalating Prices:

Kashmir prices have been increasing steadily since the late 1980s. According to connoisseur and author Benjamin Zucker, a twenty carat fine quality Kashmir sapphire was worth $25,000 per carat in 1976, though I recall an exceptional stone that sold at auction in the early 1980s for $12,500 per carat. By the turn of the last century prices for extra-fine examples at auction passed $100,000 per carat. Pricing must be taken with a grain of salt. Given varying qualities, the vicissitudes of auction houses, and the lack of any real standardized grading system, it is difficult to compare stone to stone.

Prices for premium gemstones, fancy color diamonds, type IIa colorless diamonds, ruby, sapphire, emerald and lately spinel, have all increased markedly since the 2008 bust. This can be traced to a lack of confidence in paper currencies, generally, and the dollar and Euro in particular.

Connoisseurship–Opinions Vary:

Bear Williams of Stone Group Labs, the first gem laboratory to evaluate the new record holder, was impressed. “My hair kinda stood up on end, it had some sort of magic,” he said describing his first look at the sapphire. When Williams saw it, the stone weighed over 27 carats before it was re-cut slightly and re-polished. From all indications the stone is quite superior to the Hill Sapphire, which American Gem Labs President Christopher Smith described as a “nice stone.” in 2007. Smith rated the former record holder, the Hill Sapphire, at an 8-8.5 on a 1-10 scale. Williams puts this new one well into the 9s, “maybe a 9.8” he says. Chris Smith at American Gem Labs, who did a full quality evaluation, gives the stone an overall Total Quality Integration Rating (TQIR) of Exceptional and a color grade of 2.5 (1-10 scale). Note that AGL’s TQIR factors in rarity, together with quality factors. A five carat Kashmir or the same quality would be graded Excellent.

Boldly Going Where No Lab Rat Has Gone Before

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Boldly going where No Lab-rat has gone before.

by Richard W. Wise, G.G.

Gemological Laboratories are under increasing pressure to add quality grading to their traditional role of determining origin and treatment of gemstones. One laboratory, AGL had been doing this for several years. However, recently under the aegis of the Lab Harmonizing Committee several of the leading labs have decided to aggressively go where no lab has gone before into the world of marketing. Gem Labs have entered the nomenclature business and into a firestorm of controversy .

The question of nomenclature is often more about tradition than science. You can study internal inclusions and make a determination about treatments and point out what specific anomalies led to your conclusions but how do you decide what to name a gem? The recent flap over Mozambique cuprian tourmaline that I covered in an earlier post is an excellent example. http://gemwiseblogspotcom.blogspot.com/2006_06_01_archive.html

Traditionally we name a gemstone based on species and variety but what happens in the case of a gem that is of the species corundum but derives its name strictly from a mix of colors? What gem am I thinking of? I’ll give you a hint; padparadscha sapphire.

In my book Secrets Of The Gem Trade, The Connoisseur’s Guide To Precious Gemstones, www.secretsofthegemtrade.com, following the late great GIA gemologist Richard Liddicoat, I define padparadscha as a light to medium tone of pinkish orange to orangey pink. Up until recently, labs have avoided the issue by simply calling the colors; “pinkish orange” and so forth.

A consortium of gem labs under the title: The Laboratory Manual Harmonization Committee (LMHC) met in Milan and has drawn up a standardized definition of padparadscha. The LMHC consists of seven of the world’s major 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). Some of these labs, excluding for the moment GIA-GTL, have begun to call and consumers have begun to demand a lab certificate that uses the term padparadscha to describe the stone. The question is, where is this definition coming from and is this the beginning of a brave new world wherein laboratory gemologists begin to dictate to dealers and connoisseurs?

“Well”, I can hear you say, “somebody’s got to cut through all the confusion.” and I agree. But, be careful what you wish for. Leaving aside the question of how this definition was arrived at, like it or not, once established the criteria determined by the labs will become the accepted definition. Are we ready for this and what in the training of a gemologist prepares them for this role? I received my Graduate Gemologist diploma some years back and I can tell that what a neophyte Graduate Gemologist doesn’t know about quality in gemstones would fill many volumes. A newly minted G.G. is little more than an apprentice scientist. Oh sure, he learns the GIA diamond grading system but…

According to Richard Hughes well known author and gemologist with the AGTA gem laboratory which makes him one of the most prominent lab-rats, laboratories have no business making such calls. He was particularly upset by the fact that the LMHC did not include a representative from Sri Lanka at the meetings where the decision was made (I mean where does the term come from?). Hughes also had problems with the adoption of a printed color chart developed by Franck Notari (GIA Geneva). Hughes makes the point that the definition of padparadscha is fuzzy at best and he feels that the insistence on hard a fast definitions is not appropriate. As proof of this assertion, Hughes did an analysis and discovered that the magnificent 20.84 carat padparadscha (pictured above left) that sold last year at Christies falls outside the parameters as defined by the chart adopted by the LMHC.

Stay tuned…

Bangkok Soujourn Part I

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Bangkok's Chao Prya River

by Richard W. Wise, G.G.

Arrived in Bangkok on Tuesday. We had only a week and a day between returning home from Tucson and leaving again for Asia. I had agreed to give a talk at the 34th GIA Gathering on the 24th. Lecturing on jetlag. I don’t recommend it. Still our timing was good, two days after we left, the northeast was slammed with 18″ of snow.

The Gathering, hosted by Ken Scarrett, was well organized with about 100 people in attendance, good food, good wine and good talk and all books sold. It was great seeing old friends like Mark Smith, Richard Hughes and Gay and Joe Belmont. GIA has established a school here with hundreds of students coming from all over the world to study gemology in Bangkok, the colored gemstone capital of the world. It is particularly gratifying to meet and talk to this new generation of students. I find myself in awe, they come from such an interesting variety of places and backgrounds.

Ruby; The End of Burma?

Ruby production at Mong Hsu and Mogok has shut down. Production from Mogok has for years been little more than a trickle and now it appears that the “new mines” at Mong Hsu are at an end of their productive years. At any rate, according to a number of sources, both mining areas are now effectively closed.

There are few Burma rubies of any quality to be found in the Bangkok market. In many ways this resembles the situation in the late 1980s when Burma stones did not exist in the market and all that was available was mined in Thailand. Today the Thai deposits are mined out and Africa is ruby’s new hope! Compared with Mogok, a valley 20 miles long, the vast geology of East Africa’s Mozambique belt, a geologic formation stretching from from Ethiopia in the north all the way to Zanzibar possesses the greatest potential for gem production in the 21st Century.

We have had the opportunity to see a number of the newer rubies from Mozambique and Tanzania including a 16 carat piece of flattish alluvial rough from Mozambique that will likely cut an 8+ carat stone. In some cases, the color is quite marvelous, resembling the pure scarlet hues of the best of the old Thai gems.

: Very fine old Thai ruby with orange secondary hue. Some connoisseurs consider that the slight orange frames and adds saturation to the overall color. Courtesy: Richard W. Hughes:

The hue itself was often of a purer red than stones from Burma though the high iron content added a murkiness—sometimes adding an orangy secondary hue or a brownish mask that was not attractive. Both the Mozambique and Tanzanian material while geologically similar and iron bearing have measurably less iron in their composition and thus a higher degree of transparency. Much of the Mozambique resembles the old pinkish Lai Thai material that superficially resembles some Burmese. Due to the iron, the African material lacks the highly saturated ultraviolet punch of the best of Burma, though the best material is exceptionally beautiful in its own right.

More later, stay tuned!