Presents a detailed examination of about 800 samples of carbonado diamond from Brazil and the Central African Republic, including possible models for its genesis.

Evaluates the usefulness of Raman spectroscopy in distinguishing the color varieties of nephrite based on the relative ratio of Mg to Fe concentration.

Reviews the characteristics of tourmaline from pegmatites in the Luc Yen district of northern Vietnam.

A devitrified glass reminiscent of Victoria Stone is seen during the Tucson gem shows.

GIA 曼谷鉴定所为 41 颗柬埔寨-泰国红宝石出具的分析报告。

Review of Ruby & Sapphire: A Gemologist’s Guide

A rare mineral is found in a rock crystal quartz host.

A dichroic inclusion within a quartz crystal is found to be chlorapatite.

A yellow cultured pearl necklace is compared to the work of a producer specializing in freshwater pearls of all colors.

Raman analysis identifies unusual inclusions in quartz.

A new source of sapphires is found in the Tigray region of Ethiopia.

Blister pearls attached to shells are seen in both the Bangkok and New York laboratories.

Demonstrates the importance of this method in identifying diamond treatments, based on the analysis of PL maps acquired from a brownish orange HPHT synthetic diamond.

A submission to the New York lab yields an unexpected reaction to long-wave UV radiation.

Provides a visual guide to the internal features of natural, synthetic, and treated sapphires.

A rough aquamarine crystal shows an unexpected phenomenon.

Documents a visit to the upper Missouri River and Rock Creek sapphire mining areas.

A laser manufacturing remnant in a Fancy yellow diamond creates a unique specimen.

Unique natural conch pearls are studied in the New York lab.