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

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 …

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 …

While choosing a diamond is a very personal decision, evaluating a diamond should always be a matter of precision. At GIA, we are incredibly proud that our 4Cs of diamond quality continue …

Nov 24, 2015 · Diamond crystals are brought closer to the Earth’s surface through volcanic activity. Diamonds can be found in shallow alluvial deposits where the crystals settle after …

Fancy Color Diamond Dazzling brilliance. Captivating color. These are the planet’s most valued gems.

Mar 14, 2013 · The prospect of purchasing a diamond may seem daunting, but through GIA, an unbiased authority on diamonds, you have several handy resources to help you select the …

Nov 21, 2025 · This diamond shape guide will help you understand the characteristics of different diamond shapes, so you can choose the engagement ring shapes that best suit your taste, …

GIA’s 4Cs transformed the way diamond quality is determined and communicated, forever changing how diamonds are evaluated, bought and sold. The 4Cs are for everyone.

Learn what a GIA diamond is. Discover how GIA's trusted grading system based on the 4Cs ensures transparency and quality for your diamond purchase.