How Diamonds Are Made

Diamonds form deep underground over billions of years through extreme pressure and heat, then are extracted from kimberlite pipes using mining techniques that exploit the mineral's hardness. After mining, the rough diamonds are cleaned with acid, sorted by quality, and transported to Antwerp for trading and then to Surat, India, where approximately 91% of the world's diamonds are polished by skilled artisans. Finally, the polished diamonds are sent to independent gem labs where they are graded and certified based on the "4Cs"—cut, color, clarity, and carat weight—with each stone receiving a unique laser-inscribed number for authentication.