Get to know all you need about diamond – the history, facts, quality factors, treatments, imitations and much more here at GIA.

what's in a name? Diamond [dye -mund] (noun) Diamond comes from the Greek word adamas which means “invincible.” For being the hardest material on earth, that is the perfect name for this gem!

Diamond’s splendor has been appreciated for centuries, but there was not much scientific knowledge about it before the twentieth century. Since then, diamond knowledge has grown steadily, with …

Diamond forms under high temperature and pressure conditions that exist only within a specific depth range (about 100 miles) beneath the earth’s surface. Diamond’s crystal structure is isometric, which …

With an unbiased diamond evaluation, you’re free to focus on its beauty. We issue a variety of diamond reports, ranging from the GIA Diamond Dossier® to the GIA Diamond Origin Report.

The 4Cs describe the individual qualities of a diamond, and the value of an individual diamond is based on these qualities. The terms that people use to discuss the 4Cs have become part of an …

Diamond stands at the apex of the hardness scale with a value of 10. It also has the highest thermal conductivity and the highest molar density of any terrestrial material, as well as a high resistance to …

A diamond’s journey is every bit as fascinating as its sparkle. GIA’s Diamond Origin and its related resources help you tell the story of the people in the country who brought you your diamond and …

GIA’s Guide to Gemstones: Gem Encyclopedia GIA’s Gem Encyclopedia is a virtual journey through the science and lore of gemstones from across the globe. Each precious stone page features additional …

The clarity of a diamond is based on the size, location, visibility and number of inclusions or blemishes. Internal and surface reaching characteristics are called inclusions. External features are called …