Sri Lanka, formerly Ceylon, remains one of the single most important sources for fine gemstones. Especially notable are blue sapphire, pink sapphire or ruby, and yellow sapphire; alexandrite and cat's-eye chrysoberyl; and almandine and hessonite garnet. Spinel, tourmaline, zircon, moonstone, and quartz are also relatively common; they share their country of origin with several rarer gemstones as well. Most of the gem-quality material is found in alluvial deposits throughout the island, which are mined by primitive methods. In many instances, the Sri Lankan origin of the gemstone can be determined by characteristic inclusions, several of which are also discussed in this article.