Twelve-Rayed Star Sapphire from Thailand
A black star sapphire produced from eastern Thailand, showing both golden and silver rays, is studied at GIA’s Bangkok lab.
Quarterly Crystal: Wurtzite Phantom in Quartz
For the first time, wurtzite is found as an inclusion in gem material.
Gilalite Altered to Cuprite in Quartz
A Medusa quartz from Paraíba, Brazil, hosts a surprising inclusion.
Uncommon Parallel Color Zoning in a Chameleon Diamond
A diamond examined in the Carlsbad lab shows chameleon coloring in an unusual pattern.
产自巴西的达碧兹紫水晶 (英语)
Perettiite-(Y) and Tusionite Inclusions in Phenakite from Myanmar
Seldom-seen inclusions are found in a host material that is rare in its own right.
Wollastonite in Devitrified Glass Imitating Horsetail Inclusions in Demantoid Garnet
A yellowish green specimen with horsetail-like inclusions is found to be glass rather than demantoid garnet.
Gemstone Guidebook Project
A project coordinated by GIA and the NGO Pact provides a valuable educational tool to women miners in Tanzania.
Large HPHT-Treated Blue Type IIb Diamond
A look at the color zoning exhibited by the largest HPHT-treated blue diamond graded by GIA.
Merelaniite Inclusions in Tanzanite
recently identified mineral is found, in whisker-like form, in a gem-quality tanzanite host.
宝石切磨式样－定义
在这篇综合性文章中，作者分五部分探讨了有色宝石的价值要素。第一部分和第二部分发布于《宝石市场新闻》2016 年 1/2 月刊第 1 期第 35 卷；第三部分和第四部分发布于 2016 年 3/4 月刊第 2 期第 35 卷；第五部分发布于 2016 年 5/6 月刊第 3 期第 35 卷。请注意，原文没有在标题中使用术语“刻面”。但是，本系列的主旨即是刻面宝石。
Natural Blue and Black Diamonds, a Byzantine Garnet Intaglio, Yogo Sapphires, and “Kasumiga Pearls”
An overview of the Summer 2018 Gems & Gemology content.
An Early Byzantine Engraved Almandine from the Garibpet Deposit, Telangana State, India: Evidence for Garnet Trade Along the Ancient Maritime Silk Road
Analyzes the chemical composition and inclusion characteristics of this ancient artifact.
Natural-Color Blue, Gray, and Violet Diamonds: Allure of the Deep
Summarizes data collected on more than 15,000 natural blue/gray/violet diamonds examined by GIA during the last decade and examines the mechanisms that produce this color range.
蒙大纳州约戈峡谷蓝宝石的宝石学特征 (英语)
A look at the mining and distinguishing characteristics of this naturally vibrant blue sapphire.
Cultured Pearls from Lake Kasumigaura: Production and Gemological Characteristics
Examines Japanese “Kasumiga” freshwater cultured pearls, which grow in a variety of colors.
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