A study of these pearls to characterize their distinctive flame structure and examine the possibility of rotation during their formation or growth.

Characterizes black nephrite from a deposit in the Guangxi region that appears to be part of a large-scale jade formation belt in southern China.

Two pearls presented a unique challenge, as testing at three different gemological laboratories could not conclusively identify them as natural or cultured, determine a freshwater or saltwater growth environment, or specify the producing mollusk.

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

Reviews the mining history, market impact, and properties of ruby from northern Mozambique near Montepuez, now the world’s most productive source.

Shows how the color of Madagascar sapphire is lightened with heating to relatively low temperatures below 1350°C.

Three incomplete trapiche quartz make up this interesting sample.

Jewelry designer Alexandra Mor uses sustainable alternatives for elephant ivory.

Fluorite inclusions in emeralds from various localities have been reported extensively in the literature.

Although opals generally contain water in their structure, fluid inclusions large enough to be resolved with the microscope are rare; those that can be seen with the unaided eye are exceedingly rare.

Examines the basic characteristics of kimberlites and their relationship with diamonds.

Topaz is an important gemstone that occurs in various colors.

A 7.54 ct natural emerald containing a 3D helical inclusion is examined by the Tokyo laboratory.

The appearance of curved banding under short-wave UV easily identifies flame-fusion synthetic sapphire.

The interior structures of pearls are always of interest, as they are never revealed until the analysis begins.

Conclusively identifying the origin of a “hollow” pearl filled with foreign materials proves challenging.

A phantom sapphire crystal within a host sapphire crystal was recently examined at GIA’s Carlsbad laboratory.

Twelve pink sapphires undergo low-temperature heat treatment and reveal a correlation with the 3232 cm-1 FTIR peak.