Orange Calcite
Calcite var. Orange · Semi-Precious Gemstone / Decorative Mineral Specimen
Crystal System
Trigonal (Hexagonal scalenohedral); habit is typically massive or rhombohedral in this variety
Mineral Group
Carbonates (Calcite Group)
Chemical Formula
CaCO3 (Calcium Carbonate) with possible inclusions of Iron Oxide or Hematite
Formation Process
Commonly sedimentary through chemical precipitation or hydrothermal via hot springs and mineral-rich veins
About This Crystal
Translucent to opaque massive specimen with a bright orange to honey-yellow hue. It exhibits a waxy, 'soapy' luster and characteristic rhombohedral cleavage planes visible on the surface.
Physical Characteristics
Color: Orange/Peach; Streak: White; Cleavage: Perfect rhombohedral in three directions; Fracture: Conchoidal to uneven; Specific Gravity: 2.71; Fluorescence: Often red or pink under UV light
Optical Properties
Refractive Index: 1.486 - 1.658; Birefringence: Extremely high (strong double refraction); Uniaxial negative; No pleochroism
Hardness & Durability
Origin Region
Mexico (Chihuahua), Brazil, and USA; found in sedimentary limestone or hydrothermal environments
Hardness & Durability
Mohs Hardness: 3; Toughness: Poor due to perfect cleavage; Soft and easily scratched by steel or quartz
Care & Maintenance
Clean with warm soapy water only; avoid ultrasonics, steam, and acids (vinegar will dissolve it); keep away from harder stones
Rarity & Value
Common; Value is generally low, based on color saturation and size; rarely faceted, usually sold as tumbled stones or rough chunks
Special Characteristics
Highly reactive to cold dilute Hydrochloric acid (effervescence); notable for its distinct waxy surface texture
Lore & History
Historically used in carvings and as a source of lime. Traditionally associated with the Sacral Chakra, creativity, and emotional clearing in lore.