Large Green and Yellow Diamonds Colored by Nickel Impurities
Testing several large green and yellow diamond samples reveals that nickel-colored diamonds can occur in larger sizes and stronger color saturations than previously suspected.
The Type IIb De Beers Cullinan Blue Diamond
GIA’s New York laboratory reports on a 15.10 ct (17.47 × 11.53 × 7.94 mm) Fancy Vivid blue cut-cornered rectangular step cut named the De Beers Cullinan Blue diamond.
GIA 通过 GIA Source Verify™ 拓展宝石原产地服务
作为宝石学研究、教育以及以科学为基础的宝石鉴定与分级服务方面的领导者，GIA 目前正在积极拓展宝石原产地服务，致力于向零售商和消费者提供所需的钻石产地信息。
GIA 在第五届年度大赛上表彰设计新秀
加利福尼亚州卡尔斯巴德— 2 月 14 日（星期一）— 2 月 4 日，来自 GIA 卡尔斯巴德校区的 GIA 毕业生 Meghan Simmons（梅根·西蒙斯）荣获第五届 Gianmaria Buccellati Foundation Award for Excellence in Jewelry Design（吉安马里亚·布契拉提基金会珠宝设计卓越奖）。
Gemological Characterization of Peridot from Pyaung-Gaung in Mogok, Myanmar
Examines the mining and the internal, spectroscopic, and chemical features of peridot from this deposit, which possesses a rich olive green color and is available in large sizes.
Blue Sapphires from Mogok, Myanmar: A Gemological Review
A gemological analysis of blue Burmese sapphires from Mogok, based on a series of field expeditions over the last decade.
Colored Stones from the Deep
The first installment of this column discusses the formation of colored stones from the crust-mantle transition and below.
Burmese Blue Sapphire and Peridot from Mogok and a History of Emerald Mining in Habachtal, Austria
An overview of the Winter 2021 Gems & Gemology content.
Banded Turquoise from Zhushan County, Hubei Province, China
Researchers examine six specimens of banded turquoise, obtained through long-term cooperation of local miners in Zhushan County.
Blue Zircon Reportedly from Malawi
A reported new source of blue zircon in Malawi yields rough material for beautiful finished stones in the gem trade.
Two Antique Mughal Spectacles with Gemstone Lenses
Unique diamond- and emerald-lensed spectacles from the Mughal Empire were tested in GIA’s New York laboratory.
Chondrodite in Red Spinel from Mogok, Myanmar
The Bangkok lab recently encountered a single round crystal of chondrodite in red spinel, a possible indicator of Burmese origin.
Faceted Demantoid Garnet with Spectacular “Horsetail” Inclusions
Remarkable “horsetail” inclusions discovered in a demantoid garnet, while their origin and composition remain under discussion.
Monazite (?) in Quartz
Analysis of a transparent yellow angular crystal inclusion in a Brazilian rock crystal quartz host suggests monazite.
Radioactive Green Diamond
The Carlsbad lab recently encountered a 2.42 ct green diamond showing signs of radiation treatment by the use of radioactive salts.
Rainbow Graining in Diamond
One of the more subtle inclusion scenes gemologists sometimes observe in natural diamonds is the presence of crystallographically oriented structural defects known as “internal graining.”
Spiral Nacre in Natural Pearl
Nacreous pearls are known to have platelet growth resembling fingerprints or topographic maps, but a less common appearance is nacre with a concentric spiral pattern.
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