AZGem Gems

May 2016

 

gem stone and jewelry newslettergem stone and jewelry newsletter

 


The World's Most Useful
Gem & Jewelry Monthly Newsletter

Written by Carolyn Doyle for customers of
The Dorado Company

and other visitors to the azgem.com website who subscribe.

 

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Usable Gems... and a little opinion.

  

Colored Gemstone Country of Origin Determination

 

colored gemstone country of origin determination

 

Colored gemstone country of origin determination is a subject that many colored gem enthusiasts, collectors, and investors find to be important to their endeavors.

Some recent gem industry news stories on this subject have prompted questions such as... "How is it possible to know exactly which country an individual gemstone came from?" and "Why is it important to know where a specific gemstone was mined?"

Colored gemstone country of origin determination can be a significant factor in the value of an Important Jewel sold at auction - such as this Kashmir sapphire sold at auction by Sotheby's.

Colored gemstone country of origin determination can also be important to private gem collectors and museums.

 

 

colored gemstone country of origin determination

 

The origin of gems such as tanzanite and red beryl are known because these gems occur in only one location. Maybe deposits of these rare gems will be discovered in other countries someday. If so, I'm confident that origin determination criteria will be developed for them also.

While many species of gemstones can be identified as to region, country, or even the mine of origin, many commercial gem labs limit origin determination service to ruby, sapphire, and emerald.

 

 

 

paraiba tourmaline country of origin determination

 

Now that high value Paraiba tourmaline has been found in more than one continent, some labs will determine the origin of this copper nearing tourmaline.

 

 

sapphire country of origin determination

sapphire country of origin determination

Image credit: Stone Group Labs

 

For centuries gem origin was a matter of observation. If, for example, it exhibited the attributes of a typical sapphire mined in Sri Lanka, it was labeled a Sri Lanka-type sapphire. However, since more recently discovered sapphire deposits in Africa can yield stones with similar appearance, this type of origin determination is no longer sufficient.

Gem investors and collectors covet Kashmir sapphires, who's appearance is an intense velvety blue... and who's origin is known to be the Kashmir region of the Indian subcontinent. 

 

gemstone country of origin determination equipment

Image Credit: amscope.com

 

Science and laboratory instruments have given gemologists new ways to study and catalog the observable characteristics of a gemstone. The availability of documented comparison stones, the ability to determine trace elements in the makeup of a particular stone, the observation of inclusions, and other tell-tale facts can help determine that stone's origin.

 

ruby country of origin determination

 

Colored gemstone country of origin determination methods, scientific equipment, and skills have been developed over the past sixty years or so. Refining methods and improving laboratory equipment will continue to enhance the ability of gem labs to determine origin.

 

dr. gubelin

Image Credit: GIA

 

The Gemology Project has an important and interesting report available on this subject. A portion of that report is reprinted below. Next month, more of the report will be published, as we continue to explore this subject.

Origin determination

This information is courtesy of The Gemology Project

Introduction

Collectors of gemstones and minerals often attach great importance to a gemstone’s provenance or country of origin. In "A Question of Origin," according to Mr. Richard W. Hughes, (1990, [2], n.p.), formerly, there was no method of geographical origin determination for colored gemstones or diamonds; a gemstone or diamond’s “mine-type” was strictly based on overall quality and appearance or color. For example, a ruby of an “intense, highly fluorescent red” was sometimes called “Burma-type,” or “Burma-like,” even when the ruby was not mined in Burma. In the 1940’s and 1950,’s the GIA, along with others in the gemology field, developed the system of quality analysis for diamonds; and mine-types were no longer used in describing diamonds. Some examples of the mine-types used to describe diamonds are “Golcondas” or “Premiers,” and several others. Also, during the ‘40’s and ‘50’s, studies initiated by Dr. Eduard J. Gübelin, proved that it was possible to identity a gemstone’s geographical origin and sometimes even the exact mine it came from based on the gemstone’s inclusions rather than using its overall appearance (Hughes, 1990, A Question of Origin, [3], n.p.).

Father of Origin Determination: Dr. Eduard (Edward) J. Gübelin

The late Dr. Eduard J. Gübelin of Lucerne, Switzerland “devoted his life and career to unveiling the mystique of gemstones and was recognized as the authority on inclusions in gemstones. His great knowledge of mineralogy and the jewelry business combined with his passion and admiration for gemstones made him one of the founders of modern gemology and the father of gemstone origin determination (Gübelin Gem Lab, Ltd., n.d., “Legacy of Dr. Eduard J. Gübelin,” [4], n.p.).” During his 70-year career, Dr. Gübelin collected over 5,000 rare and commercial gem specimens, which included organic gemstones, from different localities. He began to determine the origin of gemstones by systematically documenting, classifying, and categorizing gemstone specimens he collected from the mines and locations he toured. Based on the microscopic features or inclusions in the gemstones he established a “strict characterization” of gem deposits. “His concept is based on the comparison of a gemstone of unknown origin with gemstones of known origin; by determining their similarity, and the degree of resemblance of gemstones from different mining sources (Gübelin Gem Lab, Ltd., September 2006, A Holistic Method to Determining Gem Origin, [5], p. 122).” In the early 1950’s, Dr. Gübelin’s gemological studies led to an increase in the interest of different mining sources, the science of gemstone geographical origin determination, and gemological laboratory country-of-origin reports which are used by every auction house today.

Mine Production

Mines produce a wide variety of gemstones, usually of low to medium quality, with the finer gemstones forming only a “tiny fraction of the whole production,” including those which are found at the most prestigious sources. The precious gemstones, ruby, sapphire, and emerald, may show price variations and some command premium prices based on their provenance since part of the colored gemstone marketing and branding concept includes origin, even though these stones may not always be of high quality. “Origin” should not be used to reflect a certain quality of colored gemstones, nor should it be used as a description of a color type (Hughes, 1990, A Question of Origin, [6], n.p.). Today, some top-quality gemstones from recently discovered deposits, such as the sapphires found in Madagascar, with similar geology as their highly-valued gemstone counterparts, are not only impressive, but are also found in remarkable sizes; yet, since they are not from a well-known or prestigious source, they are accepted as nothing more than beautiful stones by most in the trade (Gübelin Gem Lab, Ltd., July 2006, The Roots of Origin Determination, [7], p. 66). With the exception of spinel, tourmaline, pink topaz, and alexandrite, geographic origin determination is not yet available for other gemstones.

Origin Determination

Recognized for being largely responsible for the development of the science of origin determination pioneered by Dr. Eduard J. Gübelin, Gübelin Gem Lab, Ltd., determined that it is a “key requirement” for gemological laboratories to have access to an authentic and complete collection of reference stones, which have had their gemological properties properly analyzed and fully documented, and their geologic-genetic environment is known (Gübelin Gem Lab, Ltd., July 2006, The Roots of Origin Determination, [8], p. 69). The reference stone collection must contain a sufficiently high number of samples from commercially relevant mining areas and deposits worldwide which include reference stones from exhausted mines or deposits where production has ceased. It is usually very rare to be able to collect samples directly from the host rock in the mine. The research field gemologist collects sample stones from mining areas and deposits worldwide by adhering to strict criteria and guidelines for collection. Extreme care and caution are recommended before samples can be incorporated into a reference collection because receiving stones from a source other than one claimed can have disastrous results. The process and method which the sample stones are collected is fully and properly documented; and then, are compared with the analytical data from the reference collection, or gemstones from a known source, such as the mining area, geographic location, or country, to determine and confirm the origin of the collected samples. One problem research field gemologists face is that of maintaining a current and reliable population of sample stones. Since new material is being found almost daily, tracking changes of the properties and chemistry of new and old deposit production can be a daunting task (Gübelin Gem Lab, Ltd., September 2006, A Holistic Method to Determining Gem Origin, [9], p. 126). For example, the best reference stone population of Ceylon sapphires collected 20 years ago may not be as valid for comparison as recently collected samples might be (Hughes, 1990, A Question of Origin, [10], n.p.). Therefore, gemological laboratories must continuously acquire new information through research that must be repeatedly updated. Samples must be collected and updated from mines that are open or reopen every year worldwide. Some colored gemstone mines or deposits may become depleted or inaccessible due to socio-political complications which can make it quite difficult for the research field gemologist to collect specimens. Providing information on the geographic provenance of a stone is the goal of the origin determination process.

Therefore, “the goal of origin determination is to provide the geographic provenance of a gemstone and can be defined as:

  1. the attribution of a stone to a specific geological-genetic environment (or a specific type of deposit) and
  2. the attribution of a stone to a mining area, a geographic locality, or country (Gübelin Gem Lab, Ltd., July 2006, The Roots of Origin Determination, [11],p. 69)

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To be continued next month

 

 

Colored gemstone country of origin determination is an important piece of information for collector and people buying and selling higher value gems... and can be an interesting factoid for those who own gemstone jewelry to wear.

 

gem news

 

Photo Information

 

Top - Colombian emerald

Next - Tanzanite

Next - Brazilian Paraiba tourmaline

Next - Sri Lanka blue sapphire

Next - Kashmir blue sapphire

Next - Modern gem microscope

Next - Burma (Mogok( ruby

Next - Dr. Eduard J. Gübelin

Next: - Gem special offer - Chrome Diopside, the affordable emerald green gem

Next - Industry News - Iconic Las Vegas sign

Next - Dealer Product Image - Amethyst Ring in Sterling Silver

Last - Dealer Program Image - Pink Spinel and Sterling Silver Earrings

 

 

A Google search for links or images using keywords such as gems of burma or gemstones mined in colombia can return some very interesting information and websites.

 

Google

 

Gem Offer

 

gem special offer chrome diopside oval

 

Here is this month's special gem deal. 

 

Gem:     Chrome Diopside... the other natural emerald green gem. The substitute for the May birthstone

Color:     Emerald green

Quality:     Gem quality, and no visible inclusions. Our cutter in Thailand describes the stone as... Natural gem, best quality 5a green Chrome Diopside.

Color:     Siberia, Russia

Shape:     Oval 

Dimensions:     8 x 6 mm

Approximate Weight:     .1.22 carats

Price:     $48, plus shipping ($5)

Send me an email (with anti-spam) (carolynatazgemdotcom) and tell me that you want this fine gem.

We have other  shapes, sizes, and shades of gems available.

We keep gem prices low by buying quality gemstone rough worldwide, and having the rough material cut by our gem cutters in Asia.

 

gem newsletters

 

Gem Industry News

 

Las Vegas Gem and Jewelry Shows

 

jewelry week in las vegas

 

Jewelry Week in Las Vegas is upon us.

It all started with JCK Las Vegas - The Jewelry Industry's Premier Event. JCK Las Vegas bills itself as the leading jewelry event in North America. This jewelry industry trade show is open to all jewelry professionals. This four day event is huge - in several ways.

This is where jewelry retailers can learn about emerging trends in jewelry.

Every imaginable product for people working in and around the jewelry industry seems to be on display. Manufacturing equipment, hand tools, software, display lighting, packaging, and so much more.

Jewelry designers and manufacturers introduce their new lines of merchandise at this show

Table top goods, high end luggage, clocks and watches, it's all at this show.

The sheer physical size of the show is amazing. It is huge.

The American Gem Trade Association (AGTA) Gemfair Las Vegas is a companion event. Gemfair and JCK Las Vegas are held at the Mandalay Bay Convention Center. As always, this AGTA show is about loose colored gemstones.

The Gem & Lapidary Dealers Association (GLDA) Las Vegas Mirage Gem & Jewelry Show is, as the name states, a show featuring loose gems and finished jewelry. It is a more intimate show with industry respected vendors.

Other shows have been added over the past several years. Collectibles, timepieces, and other themed shows are held up and down the Strip during this time.

 

gemstone news

 

Jewelry Dealers

 

jewelry dealers wholesale

 

The Spring season lets you work both sides of your business.

As always, mine your customer list for gift occasions... anniversaries, birthdays, and more.

You can also be replenishing your inventory. Holiday sales left sucessful dealers with cash on hand and depleted inventory.

Be the Quality Jewelry Discounter.

 

 

gemstone news

 

Jewelry Dealers Program

 

jewelry dealers program

 

Do you enjoy jewelry and gems?

Do you enjoy talking with friends and friends of friends?

Could you use an extra income source?

Take a look at our great Jewelry Dealers Program.

 

 

Carolyn Doyle

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