Diamond: Science, Legend, and the Cullinan

Diamond is pure carbon pushed to perfection: 99.95 percent carbon, crystallized 150 to 250 kilometers underground, and rated 10 on the Mohs scale, about four times harder than the next contender, corundum. India mined the gems for 3,000 years before other sources appeared. The Cullinan, at 3,106 carats, remains the largest ever found, while the Hope Diamond carries its famous curse legend.

Modern lab grown diamonds are chemically identical to mined stones. Explore the full gemstone profiles, from hardness to birthstone months..