Sapphire Curation Guide: From Royal Blue and Provenance Identification to Unheated Status and Laboratory Standards

Sapphire is the collective designation for all gem-quality corundum varieties excluding red, with blue corundum colored by iron and titanium being the most iconic. Its valuation in gem curation rests upon four key dimensions: color grading, provenance, treatment status, and laboratory certification. The market holds Royal Blue and Cornflower Blue as the most highly prized color designations, with natural unheated status (no indications of heating) forming the core benchmark of physical rarity. This guide examines sapphire color grading, provenance identification across Kashmir, Burma, and Sri Lanka, the collector significance of unheated status, and evaluation standards established by leading international laboratories including AIGS, GIA, GRS, Gübelin, and SSEF.