The rough diamonds are freed from various impurities, helping a better quality of polished diamond to be manufactured from the same rough sample.
To clean impurities from within the rough diamond, the stone is subjected to vaporized gases that can penetrate microscopic cracks and work inside the stone. The cleaning process follows a unique recipe of chemicals and processes.
At the core of the process is a mixture of chemicals in an autoclave. Different chemical ratios are boiled at 250–500°C. This vaporizes the acids, expanding and building pressure inside the sealed autoclave. The pressure forces the gases into the cracks, where they digest organic materials within.