Search found 15758 matches
- Sun Jun 07, 2015 2:49 am
- Forum: Gemstones
- Topic: The Rare Chrysoberyl Called Alexandrite
- Replies: 3
- Views: 250
The Rare Chrysoberyl Called Alexandrite
Russian Alexandrite by Peter Bancroft Tokovaya Mines, Ekaterinburg, Russia Editor’s Note: We are pleased to reprint this selection from Peter Bancroft’s classic book, Gem and Crystal Treasures (1984) Western Enterprises/Mineralogical Record, Fallbrook, CA, 488 pp. "One of the best gem mines on...
- Sun Jun 07, 2015 2:44 am
- Forum: Gemstones
- Topic: Detecting Treatments
- Replies: 7
- Views: 372
Re: Detecting Treatments
GIA Identifies a Surge in Large HPHT-Treated Diamonds By JCK Staff / Posted on December 21, 2010 "The Gemological Institute of America Laboratory reported that a significant number of large high-pressure/high-temperature-treated color diamonds were recently submitted for grading. Ranging from ...
- Sun Jun 07, 2015 2:43 am
- Forum: Gemstones
- Topic: Detecting Treatments
- Replies: 7
- Views: 372
Re: Detecting Treatments
Distinguishing Heated Spinels from Unheated Natural Spinels and from Synthetic Spinels A short review of on‐going research Sudarat Saeseaw, Wuyi Wang and Kenneth Scarratt GIA Laboratories, Bangkok and New York John L. Emmett and Troy R. Douthit Crystal Chemistry, Brush Prairie, Washington Updated M...
- Sun Jun 07, 2015 2:43 am
- Forum: Gemstones
- Topic: Detecting Treatments
- Replies: 7
- Views: 372
Re: Detecting Treatments
Enhancements or "Treatments" "As in other gemstones, 99% of all emeralds are enhanced with a liquid or resin after cutting. Similar practices are carried out on diamonds (ie. laser drilling, etc.), sapphires (ie. glass filling) and most other gemstones. All post-cutting processes are...
- Sun Jun 07, 2015 2:42 am
- Forum: Gemstones
- Topic: Detecting Treatments
- Replies: 7
- Views: 372
Re: Detecting Treatments
A Review of Current Challenges for the Identification of Gemstones by James Shigley A review of current challenges for the identification of gemstones "A variety of treated and synthetic gem materials are encountered today in the jewelry marketplace in increasing quantities. Although normally ...
- Sun Jun 07, 2015 2:41 am
- Forum: Gemstones
- Topic: Detecting Treatments
- Replies: 7
- Views: 372
Re: Detecting Treatments
This article by John Koivula, recently released by GIA Research, has some fascinating shots of what to look for: "A Question Concerning Heat-Treated Blue Sapphires" John I. Koivula and Alethea Inns; GIA Laboratory, Carlsbad "Over the past several years, we have noted a curious pattern...
- Sun Jun 07, 2015 2:40 am
- Forum: Gemstones
- Topic: Detecting Treatments
- Replies: 7
- Views: 372
Re: Detecting Treatments
A wonderfully clear explanation, thanks. It's a shame so many dealers fail to disclose these treatments, even when the low price means something must be going on. I'm so glad you let us know you found it interesting and informative, Gemjunkie. Thanks! Non-disclosure is a major problem in the indust...
- Sun Jun 07, 2015 2:39 am
- Forum: Gemstones
- Topic: Detecting Treatments
- Replies: 7
- Views: 372
Re: Detecting Treatments
Thanks for the great links! Oh good. Here's another wonderful article by Richard Hughes that reveals how flux is used to 'heal' rubies by treaters, and Mother Nature as well. Enjoy! Fluxed Up The Fracture Healing of Ruby By R.W. Hughes Flux healing of Mong Hsu ruby from Burma "Just what treatm...
- Sun Jun 07, 2015 2:37 am
- Forum: Gemstones
- Topic: Detecting Treatments
- Replies: 7
- Views: 372
Detecting Treatments
Excellent articles and pics by John Koivula: The Role of Secondary Fluid Inclusions in Detecting Heat Treatment John I. Koivula GIA Laboratory, Carlsbad, California (April 30, 2009) m Micro-Magma Chambers in Natural Rubies and Sapphires: The Behavior of Some Mineral Inclusions in Corundum At High Te...
- Sun Jun 07, 2015 2:30 am
- Forum: Gemstones
- Topic: Cat's Eye Apatite - Lemon Yellow
- Replies: 1
- Views: 174
Re: Cat's Eye Apatite - Lemon Yellow
Gosh KJ, I've never even seen the stuff.