Ruby
Corundum var. Ruby · Precious Gemstone
Crystal System
Trigonal (Hexagonal); typically occurs as hexagonal prisms, bipyrandoids, or rhombohedrons.
Mineral Group
Oxides (Hematite group)
Chemical Formula
Al2O3 with Cr (Chromium) trace elements
Formation Process
Metamorphic or Igneous; typically forms in aluminum-rich, silica-poor environments under high heat and pressure, or in contact metamorphism of limestone.
About This Crystal
An oval-cut, translucent to semi-opaque red gemstone with a vitreous to sub-adamantine luster. This specific specimen shows visible internal inclusions and a slightly desaturated 'pigeon blood' to pinkish-red hue, surrounded by a halo of colorless accent stones.
Physical Characteristics
Color: Red (pinkish to purplish red). Streak: White. Cleavage: None (has parting). Fracture: Conchoidal to uneven. Specific Gravity: 3.97-4.05. Fluorescence: Strong red under longwave UV (due to chromium).
Optical Properties
Refractive Index: 1.762-1.770. Birefringence: 0.008. Pleochroism: Strong (purplish-red to orange-red). Dispersive Power: 0.018. It is Uniaxial negative.
Hardness & Durability
Origin Region
Myanmar (Burma), Mozambique, Thailand, Vietnam, and Sri Lanka. Often found in marble-hosted deposits or basaltic environments.
Hardness & Durability
Mohs Hardness: 9. Excellent durability and toughness, though surface-reaching inclusions or fractures can affect stability.
Care & Maintenance
Wash with warm soapy water and a soft brush. While usually safe for ultrasonic cleaners, caution is advised if the stone has been glass-filled or heavily fractured. Avoid harsh chemicals and sudden temperature changes.
Rarity & Value
Rare to Extremely Rare in high quality. Value is dictated by color (saturation), clarity, and origin. Many rubies in modern jewelry are heat-treated or lead-glass filled to improve appearance.
Special Characteristics
Strong red fluorescence. This specific stone appears to have heavy internal 'silk' (rutile needles) or inclusions, common in natural untreated or minimally treated material.
Lore & History
Historically known as the 'King of Precious Stones.' Traditionally associated with the base chakra, passion, and protection. Used by ancient Sanskrit cultures to provide safety from enemies and in medieval Europe to ensure health and wealth.