A survey of recent advances in CVD synthetic diamond quality.

G&Gは、2019年 Edward J. Gübelin 博士最優秀記事賞の受賞者を発表します。

この地域の地質と調査中に観測されたサンプルの説明を含め、この新たに発見された鉱床でのサファイア採掘と取引状況を詳細に説明。

A classic two-circle reflecting goniometer was used to measure inter-facet angles on five faceted diamonds that included round brilliants and fancy shapes.

ジェダイトとオンファサイトとの識別の調査に加えて、これらの石の定義に関するGIAの現在の方針。

Since the 1970s, Brazil has been a consistent source of emerald.

Dye treatments in yellow or “golden” cultured pearls have improved to the point that some samples show little surface evidence.

A presentation of parameters used to support GIA's symmetry grading system.

Twenty-six peridot samples from the Esquel pallasite meteorite and 27 samples from 10 terrestrial sources were studied by laser ablation.

珍しい鮮やかな紫の実体色と強い遊色効果を持つオパール群の検査。

Opals with an unusual purple bodycolor and strong play-of-color have recently appeared in the market.

A compilation of ongoing research into red feldspar and its sources around the world, as well as the detection of various color treatment processes.

The existence of a natural red andesine deposit in China/Tibet has been the subject of controversy since 2006.

Red copper-containing plagioclase feldspar from Oregon has been available for over a century.

Natural-color saltwater cultured pearls from Pinctada margaritifera were studied by diffuse reflectance UV-Vis-NIR spectroscopy.

Pietersite has been described as a brecciated variety of tiger’s-eye.

A 52.49 carat near-round “pearl” is submitted to the Bangkok laboratory as a “Melo pearl.”

An examination of synthetics in the marketplace over the first decade of the 2000s.