This 146.10-carat peridot is in the collection of the Natural History Museum in London Peridot has always been associated with light. In fact, the Egyptians called it the “gem of the sun.” Some ...

Two major issues related to emerald are origin determination and the presence and quantity of fillers. An emerald’s value depends in part on the quality of the stone and treatments applied, so ...

Laser sawing of diamonds is beginning to revolutionize the diamond-cutting industry. Not only does the laser saw offer savings in time and money, but it also enables the cutting of material virtually ...

CARLSBAD, California – December 11, 2024 – Recognizing the industry’s interest in more information about the nature of fillers in emeralds, GIA will offer filler identification with its emerald ...

Diamond is available in a range of sizes and qualities to fit every consumer's tastes. One of the first things most people learn about diamonds is that not all diamonds are created equal. In fact, ...

In 2009, GIA bestowed its highest honor, the Richard T. Liddicoat Award for Distinguished Achievement, on longtime chief research gemologist John I. Koivula. The award was based on his contributions ...

Practice the same time-tested procedures and identification skills used by the Institute’s renowned gemological experts. Tools used include a microscope, a refractometer with polarizing filter and a ...

This study investigated the effectiveness of a handheld magnet in detecting synthetic diamonds. A total of 104 synthetic diamonds from nine different manufacturing sources were tested. Of the ...

GIA Instruments works hand-in-hand with GIA’s laboratory, education and research teams, as well as the jewelry trade to develop the instrumentation you need to prepare you for the challenges of ...

Due to the overwhelming popularity of GIA’s limited time, no-charge offer, all GIA Essentials classes starting in May and June – the period of the offer – are full. The offer is closed and we cannot ...

Fine-color, large, and eye-clean (lacking visible inclusions) rubies like this 11.01carat (ct) stone from Myanmar (formerly known as Burma) are extremely rare and valuable. – Photo: Robert Weldon/GIA.

As a consumer, you will regularly encounter in the marketplace gems that have been treated to change their appearance. A topic that often comes up is whether a particular gemstone is or isn’t treated.