Ruby
Corundum var. Ruby · Precious Gemstone
Crystal System
Trigonal, typically forming barrel-shaped, prismatic, or tabular crystals, often heavily modified
Mineral Group
Oxides
Chemical Formula
Al2O3 (with trace amounts of Cr3+ substituting for Al3+)
Formation Process
Metamorphic and igneous processes, specifically through regional or contact metamorphism of aluminum-rich sedimentary rocks (marbles) at high temperatures and pressures
About This Crystal
Faceted small spherical beads exhibiting a vibrant pinkish-red to deep red color, translucent to transparent clarity, and a vitreous to sub-adamantine luster with minor surface facets
Physical Characteristics
Color is vivid red; streak is white; crystal habit is typically tabular or prismatic (though here fashioned into faceted beads); no true cleavage, exhibits parting; fracture is conchoidal to uneven; specific gravity is approximately 4.0; brittle tenacity; displays strong red fluorescence under longwave UV light
Optical Properties
Doubly refractive with uniaxial negative optical character; strong dichroism showing purplish-red and yellowish-red from different crystal angles; refractive index ranges from 1.762 to 1.770
Hardness & Durability
Origin Region
Notable sources include Myanmar (Burma), Thailand, Mozambique, Madagascar, and Sri Lanka; typically forms in marble-hosted deposits or metamorphic terrains
Hardness & Durability
Mohs hardness of 9, making it extremely durable and second only to diamond, with excellent wearability for daily jewelry use and high resistance to scratching
Care & Maintenance
Safe to clean with warm soapy water, ultrasonic cleaners, and steam cleaners (unless fractured or heavily included); store away from harder stones like diamonds to prevent scratching other materials; highly stable and resistant to chemicals
Rarity & Value
Rarity ranges from uncommon to extremely rare depending on size, clarity, and provenance (such as coveted 'Pigeon's Blood' Burmese rubies); widely treated via heat enhancement to improve color and clarity
Special Characteristics
Strong red fluorescence under ultraviolet light due to chromium content; asterism can occur in cabochon cuts displaying a six-rayed star, though not present in these faceted beads
Lore & History
Historically revered as the 'King of Gems' in ancient Sanskrit texts, symbolizing passion, vitality, and power; associated with the root chakra in modern crystal healing traditions as a stone of life force and courage