Many of the important gem minerals seen on today's market - aquamarine, tourmaline, and topaz, among others - come from an unusual type of rock known as a pegmatite. Gem-bearing pegmatites are ...

During the past 25 years, the corundum market has been transformed from one of medium to high-priced gems to one that encompasses nearly all price ranges. This transformation was caused by the ...

The market value of jadeite has risen dramatically in recent decades, often rivaling that of fine ruby and sapphire. Understanding the color origin of jadeite and reliably determining treatments have ...

The soothing soft pink shades of rose quartz appeal to gem carvers and collectors. – Valerie Power, courtesy Arunashi People accept a certain amount of sand, dirt, and dust as ordinary ingredients in ...

Nephrite jade with high market value and production potential from the Chinese city of Hechi, in Guangxi Province, was tested by standard gemological methods, polarizing microscopy, scanning electron ...

Whether you're taking your next step in your professional journey or starting a new career, GIA courses and diploma programs prepare you for success. With curriculum developed from groundbreaking ...

Colorless to yellow to intense orange sapphire will react quite differently to light or heat depending on the nature of the material and the origin of the color. The authors determined that there are ...

Diamond “type” is a concept that is frequently mentioned in the gemological literature, but its relevance to the practicing gemologist is rarely discussed. Diamonds are broadly divided into two types ...

Studies carried out at the DTC Research Centre have shown that single-crystal CVD synthetic diamond is clearly distinguishable from natural diamond. This article presents information about the CVD ...

Learn the product knowledge and grading skills to effectively buy inventory and build confidence when buying and selling akoya, South Sea, Tahitian and freshwater pearls. You will be taught GIA’s 7 ...

Miners collect spinels from gravel at the end of a long day at Man Sin. Photo by Vincent Pardieu, © GIA. In the spring of 2001, I was studying gemology in Yangon ...

Figure 1. The bright red faceted ruby in this gold ring is from the large and potentially productive Snezhnoe deposit in Tajikistan. Photo by Zamoniddin Z. Nasriddinov. Discovered during the late ...