Blue Sapphire
Corundum var. Sapphire · Precious Gemstone
Crystal System
Trigonal, typically forming barrel-shaped, bipyramidal, or tabular crystals
Mineral Group
Oxides
Chemical Formula
Al2O3 (with trace amounts of Fe and Ti)
Formation Process
Metamorphic and igneous processes, typically forming in marble, bauxite-rich weathering zones, or alkali basalts and pegmatites
About This Crystal
Faceted round brilliant cut gemstone displaying a vibrant blue color, high transparency, and exceptional adamantine to vitreous luster with internal light dispersion and bright scintillation.
Physical Characteristics
Blue body color with a white streak, conchoidal to uneven fracture, no true cleavage (parting may occur along rhombohedral planes), specific gravity of approximately 3.99 to 4.10, and brittle tenacity.
Optical Properties
Uniaxial negative with a refractive index ranging from 1.762 to 1.770, strong dichroism showing blue and greenish-blue hues from different angles, and high brilliance due to faceting.
Hardness & Durability
Origin Region
Kashmir, Myanmar (Burma), Sri Lanka (Ceylon), Madagascar, Australia, and Thailand
Hardness & Durability
Mohs hardness of 9, making it extremely durable, scratch-resistant, and ideal for everyday jewelry wear with high resistance to chemicals and thermal stability.
Care & Maintenance
Can be safely cleaned with warm soapy water, ultrasonic cleaners, or steam cleaners. Store away from other gems to prevent scratching softer materials, though it can scratch almost any other gemstone.
Rarity & Value
Rare to very rare depending on size, clarity, and unheated origin. Value is heavily dictated by color saturation, lack of inclusions, and absence of heat treatments or enhancements.
Special Characteristics
Exceptional dispersion and brilliant-cut faceting effects creating intense light return; may exhibit asterism or color zoning in rough forms, though cut stones emphasize high clarity and uniform color.
Lore & History
Historically associated with royalty, divine favor, wisdom, and spiritual clarity. Often used in ancient lore to protect against negative energy and psychic attacks, traditionally linked to the third eye and throat chakras.