What is Boule?

A boule is a synthetic or lab-grown crystal that is produced through the process of crystal growth, typically used in the creation of synthetic gemstones. It is a large, cylindrical-shaped crystal ingot that is created by melting the raw materials and then slowly cooling them under controlled conditions. Boules serve as the starting material for cutting and faceting synthetic gemstones, providing a consistent and homogeneous material for the production of lab-grown diamonds, rubies, sapphires, and other gemstone varieties.