Thursday, January 11, 2007

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:

  1. 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.

  1. 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:

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


JP said...

Dear Mr Wise:

I have already purchased your book and love your prospective of the industry and your candid nature regarading the business of gems stones.

I have recently purchased a stone from DSN and think it is a type of Alexandrite. However I have never heard of the stone and can not find out much information about it.

It also may be a type ot tourmaline???

Therefore, i am asking for your help in determining what the hardness of the stone is and the best way to set the stone.

It is called a Kagarco K type and is 9.64 ct oval with 11.5 X 12.5 .

If you have any semi mounts that you could sell I would be interested as a trust your judgement and love your designs.

If you have ever heard of this type of stone and have a nice setting I would love to talk.

Best Regards,

John Perrotto
81 Bluff Hill Acres Marthasville, MO

Richard W. Wise said...

Ya got me. Kagarco K type sounds like a radioactive isotope not a gemstone. Love the shopping channels those folks come up with some creative stuff. Well if you don't know the answer just make something up.

Try asking the question at there are a few shopping channel aficanados on the forum who, no doubt, will be able to answer your question.

Will give you a call on your setting problem. By the way we do handmade originals don't have a semi-mount in the place.


Alain said...


200,000 livres

Alain said...


I would like to retract the former quiz guess (as that was for the Sancy, not the Hope).

My answer to the quiz is according to Tavernier's calculations: 714,150 livres

Anonymous said...

So do I win the book? In 1691 the value of the hope diamond was the equivalent of around $3.6 million.
Gloria Reus Thayer

Anonymous said...

So do I win the book? In 1691 the value of the hope diamond was the equivalent of around $3.6 million.
Gloria Reus Thayer

Anonymous said...

In 1691 the value of the hope diamond was the equivalent of around $3.6 million = 1854.714064 livres
Gloria Reus Thayer

Kristina said...

600,00 livres??

KMoussally said...

Guess PM'd to you at gemologyonline.

leach said...

That's certainly going to have an interesting effect on how gemstones are graded in the near future. I can't wait!

Richard W. Wise said...


No one is really close.

I am off to Africa; Namibia, Cape Town, Moputo and Monbasa. Hopefully will be able to communicate with my laptop. Will keep you up to date on adventures, if any.

Karim points out that there may be a problem with my decimal point in the equivelence between Seventeenth Century French livres and current dollars but Hint: Read the question.

Hope to the second part of Rocky Road before I leave.


Patrick Slavenburg said...


I hope you have an interesting time in Africa.

I think the value is 3 million livres though it was given to the stone of 67 carats according to Streeter. (total of 600.000 US$).

See you in Tucson perhaps ?