Ruby
Corundum variety Ruby · Precious Gemstone
Crystal System
Trigonal; typically hexagonal tabulate or prismatic crystals
Mineral Group
Oxides (Hematite group)
Chemical Formula
Al2O3 with Cr trace elements (Chromium)
Formation Process
Metamorphic (usually in marble or schists) or Magmatic (pegmatites or basalts)
About This Crystal
Deep pinkish-red to vivid red oval-cut faceted gemstone; translucent to transparent with visible natural inclusions (silk/needles) and vitreous luster.
Physical Characteristics
Primary red color; white streak; no cleavage; conchoidal to uneven fracture; high density (3.97-4.05 SG); strong red fluorescence under UV light.
Optical Properties
Refractive Index 1.762-1.770; Birefringence 0.008; Strong dichroism (purplish-red to orangey-red); Singly refractive (uniaxial negative).
Hardness & Durability
Origin Region
Myanmar (Burma), Mozambique, Thailand, Madagascar, and Vietnam
Hardness & Durability
Mohs hardness 9; Excellent toughness and stability; highly durable for daily jewelry wear.
Care & Maintenance
Safe with warm soapy water; generally safe for ultrasonic cleaning unless heavily fracture-filled; avoid harsh acids and extreme heat.
Rarity & Value
Very Rare; value determined by pigeon-blood color, clarity, and origin; frequently heat-treated or lead-glass filled to improve appearance.
Special Characteristics
Features visible color zoning and natural 'silk' rutile inclusions; classic red fluorescence which enhances body color in sunlight.
Lore & History
Historically known as the 'King of Precious Stones' (Ratnaraj in Sanskrit); symbolizes passion, protection, and prosperity; associated with the Heart and Root chakras.