Orange Calcite
Calcite var. Orange (Calcium Carbonate) · Semi-Precious Gemstone / Mineral Specimen / Decorative Stone
Crystal System
Trigonal; typical habit in this specimen is massive or rhombohedral with distinct cleavage planes visible on the surface.
Mineral Group
Carbonates; Calcite group.
Chemical Formula
CaCO3 (frequently contains trace inclusions of hematite or limonite which provide the orange color)
Formation Process
Sedimentary or Hydrothermal; forms through chemical precipitation in marine environments or from hot, mineral-rich solutions in veins and cavities.
About This Crystal
A translucent to opaque specimen with a vibrant honey-orange to light-orange hue. It possesses a waxy to vitreous luster and shows the characteristic rhombohedral cleavage steps typical of the calcite species. The texture appears somewhat coarse and granular in areas.
Physical Characteristics
Color: Orange; Streak: White; Cleavage: Perfect rhombohedral in three directions; Fracture: Uneven to sub-conchoidal; Specific Gravity: 2.71; Tenacity: Brittle; Fluorescence: May show weak red or orange under UV light.
Optical Properties
Refractive Index: 1.486 - 1.658; Birefringence: Extremely high (0.172); Optically Uniaxial (-); No significant pleochroism in massive forms.
Hardness & Durability
Origin Region
Major sources include Mexico (notably Chihuahua), Brazil, and the USA. Found often in sedimentary and hydrothermal environments.
Hardness & Durability
Mohs Hardness: 3 (soft); Toughness: Poor due to perfect cleavage; Sensitive to most acids and heat. Not recommended for high-wear jewelry like rings.
Care & Maintenance
Clean only with warm soapy water and a soft cloth; avoid ultrasonic cleaners and steam. Keep away from acids (including vinegar/citrus) and sharp objects which can easily scratch the surface.
Rarity & Value
Common; Value is generally low, determined by color saturation and size. Often sold as tumbled stones or large rough decorative chunks. Rarely treated.
Special Characteristics
Displays strong double refraction (birefringence) when clear; this specific specimen is notable for its waxy luster and saturated orange coloration caused by iron oxide inclusions.
Lore & History
Historically used in decorative carvings. In metaphysical traditions, it is associated with the Sacral Chakra and believed to enhance creativity, playfulness, and emotional healing. These are cultural beliefs and not scientifically validated.