Unheated material from a sapphire deposit in southern Colombia is examined in GIA’s Carlsbad lab.

Faint green HPHT synthetic diamonds recently submitted to the Carlsbad lab owe their color to high concentrations of nickel.

GIA’s Hong Kong laboratory examines a freshwater bead-cultured pearl necklace possessing several interesting features.

Two flame-fusion synthetic sapphires with a Paraíba-like color are examined at GIA’s Carlsbad lab.

A look at the rare and unusual gem and mineral market.

A report from the Accredited Gemologists Association (AGA) Conference, held in Tucson, Arizona, on February 6, 2019

An obituary detailing the many contributions of gemologist E. Alan Jobbins.

A garnet proves to have a much higher grossular component than initially expected.

A purple fluorite contains an elongate, rod-shaped beryl crystal.

An examination of the skull-melting technique used to produce cubic zirconia, first introduced in 1976, as well as the market status of this diamond simulant and information about its production and quality.

This article discusses the results of an experiment conducted on heat-treated lavender jadeite.

This article describes the method of culturing these

An overview of some of the most fabulous and famous diamonds that Harry Winston has known.

Two major sources of error make spectroscopically determined color grades unreliable.

The authors examine an unusual crystal in matrix.

Anatase crystals create stunning blue interference colors in a Brazilian quartz host.