Orange Calcite with Host Rock
Calcite var. Orange · Decorative Stone / Mineral Specimen
Crystal System
Trigonal; massive and rhombohedral habit, often appearing as grainy or crystalline veins within matrix
Mineral Group
Carbonates (Calcite Group)
Chemical Formula
CaCO3 (Calcium Carbonate) with trace Iron (Fe) or Hematite inclusions for color
Formation Process
Formation through sedimentary precipitation or hydrothermal processes where calcium-rich fluids crystalize in rock fractures
About This Crystal
The image shows a vibrant orange crystalline vein embedded in a gray-brown, coarse host rock. The orange material exhibits a grainy, translucence with a vitreous to waxy luster, while the surrounding matrix is textured and opaque.
Physical Characteristics
Color: Bright orange; Streak: White; Cleavage: Perfect rhombohedral in crystal form, though often massive in veins; Specific Gravity: 2.71; Fluorescence: Often exhibits orange or red fluorescence under longwave UV.
Optical Properties
Refractive Index: 1.486 - 1.658; Birefringence: 0.172 (extremely high); Uniaxial negative; no significant pleochroism in massive form
Hardness & Durability
Origin Region
Mexico (notably Chihuahua), United States, Brazil, and China; often found in sedimentary limestone or metamorphic marble deposits
Hardness & Durability
Mohs Hardness: 3; Toughness: Poor due to perfect cleavage; sensitivity to acids and heat makes it delicate for jewelry
Care & Maintenance
Avoid all acids (vinegar/lemon juice) as it will dissolve; clean only with warm soapy water and a soft cloth; keep away from harder stones to prevent scratching
Rarity & Value
Common; Value is generally low to moderate based on color intensity and size; treatments such as acid-dipping are common to create a smooth, 'soapy' surface texture
Special Characteristics
Effervesces (fizzes) instantly when in contact with dilute hydrochloric acid; high birefringence can cause double-refraction in clear specimens
Lore & History
Historically used as a carving material for ornaments; in metaphysical traditions, it is associated with the sacral chakra and believed to promote creativity and emotional energy