Corundum

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Mineral guide

Learn about Corundum

iconic mineral with ruby and sapphire varieties; Mohs 9, vivid colors, and sharp crystals; prized for color, form, and provenance.

Regional guide

Corundum from Mogok Valley, Myanmar

Mogok Valley is the classic collector’s name behind the finest Burmese corundum: ruby in marble, sapphire from the surrounding metamorphic and intrusive complex, and the rare specimens that preserve this geology rather than disappearing into the cutting wheel. The most desired pieces are not simply red or blue stones from Myanmar; they are specimens with locality character—ruby crystals glowing against sugary white calcite or marble, sapphire crystals from named Mogok districts, and corundum associated with the marble-suite minerals that make the Stone Tract recognizable to gemologists and mineral collectors alike.