

切工:4C 的第四个标准
自 2006 年,GIA 开始将圆形明亮式钻石的切工等级纳入其鉴定证书,旨在以与颜色和净度相同的方式制定切工标准。 此切工分级系统以此前十年间进行的研究为基础;研究成果发表于《宝石与宝石学》(Gems & Gemology) 刊载的数篇文章中。

世界宝石产地浪漫之旅:巴西克鲁塞罗矿
跟随 GIA 实地宝石学家的脚步,前往巴西克鲁塞罗碧玺矿,开启一段真正的宝石开采冒险之旅。 该矿每年生产 8 吨碧玺,同样如此让人兴奋不已的有色宝石产地少之又少。




Investigation into Invalidated Reports Continues: GIA Offers No-Cost Confirmation Service



A Jadeite Bangle Simulant: Hydrogrossular Garnet
Bangles submitted for identification are found to be not jadeite jade, but hydrogrossular garnet, an unusual choice for this form.

Modified Rheinberg Illumination
A lighting method modified for gemological microscopy provides false-color contrast to enhance inclusion scenes.

Irradiated Green-Blue CVD Synthetic Diamonds (英语)
Advancing CVD growth technologies yield intensely colored, high-quality synthetic diamonds, such as the two green-blue synthetic materials seen in the New York lab.

Assembled Cultured Blister Pearl with an Unusual Component
An assembled mabe pearl contains a fluted object, the function of which is unknown.

Large Star Emerald
An emerald reportedly from Madagascar is cut to show asterism, a rare phenomenon in this material.

Rare “Star and Cross” Quartz from Brazil
Two quartz specimens showing asterism and cross-shaped inclusions are analyzed.

Impregnated and Dyed Turquoise
Natural turquoise has been subjected to dyeing and three types of impregnation.

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