Heat Treatment in Ruby and Sapphire: A Practical Guide for Buyers

The vast majority of rubies and sapphires in the market have undergone heat treatment to improve colour and clarity. Unheated stones command premiums when quality merits it and documentation supports the claim.

Reports typically state "no indications of heating" or describe standard heat treatment. Buyers should not conflate treatment status with origin or with synthetic identification — each requires distinct laboratory tests.