Sapphire
Corundum var. Sapphire · Precious Gemstone
Crystal System
Trigonal, typically forming barrel-shaped, tapered prismatic crystals or bipyramidal habits.
Mineral Group
Oxides
Chemical Formula
Al2O3 (with trace amounts of Fe, Ti, Cr, V)
Formation Process
Forms primarily in igneous environments such as silica-deficient pegmatites and alkali basalts, or through regional and contact metamorphism of aluminum-rich rocks like marble.
About This Crystal
The jewelry piece features a central light-colored or clear oval-cut gemstone flanked by deep blue sapphire accents. The blue accent stones display a rich, saturated blue coloration, vitreous luster, and high transparency.
Physical Characteristics
Body color ranges from deep blue to colorless (for the central stone), white streak, absence of true cleavage (exhibiting parting instead), conchoidal fracture, specific gravity around 4.00, and brittle tenacity.
Optical Properties
Singly refractive to uniaxially negative double refraction with a high refractive index (1.762-1.770), strong dichroism visible in colored varieties, and high adamantine to vitreous luster.
Hardness & Durability
Origin Region
Notable sources include Kashmir, Myanmar (Burma), Sri Lanka, Madagascar, Thailand, Australia, and the United States (Montana).
Hardness & Durability
Mohs hardness of 9, making it exceptionally durable, tough, and resistant to scratching, highly suitable for everyday jewelry use.
Care & Maintenance
Safe to clean with warm soapy water, ultrasonic cleaners, and steam cleaners (unless heavily included or fracture-filled). Store separately from softer stones to prevent scratching.
Rarity & Value
Rarity and value depend heavily on color saturation, clarity, size, and geographic origin. Unheated fine blue sapphires command high prices; heat treatments are very common to improve color and clarity.
Special Characteristics
Can exhibit asterism (star sapphire) due to microscopic rutile silk inclusions, and sometimes color-change properties resembling alexandrite.
Lore & History
Historically worn by royalty and clergy as a symbol of wisdom, divine favor, purity, and spiritual enlightenment. Associated with the throat and third-eye chakras in modern crystal healing traditions.