Orange Calcite
Calcite var. Orange (Calcium Carbonate) · Semi-Precious Gemstone / Decorative Stone / Mineral Specimen
Crystal System
Trigonal; typically occurs in massive form, though can form rhombohedral or scalenohedral crystals. Twinning is common in calcite crystals.
Mineral Group
Carbonates (Calcite Group)
Chemical Formula
CaCO3 (frequently with iron or manganese impurities giving it the orange hue)
Formation Process
Primarily Sedimentary through chemical precipitation or biogenic processes. Also occurs in Metamorphic (marble) and Hydrothermal (vein filling) environments.
About This Crystal
Tumbled and polished specimen featuring a warm honey to deep orange color. It exhibits a waxy to vitreous luster with internal white veining and cleavage planes. The specimen is translucent to semi-opaque with visible depth.
Physical Characteristics
Color: Orange to honey-yellow; Streak: White; Cleavage: Perfect rhombohedral in three directions; Fracture: Conchoidal to uneven; Specific Gravity: 2.71; Fluorescence: Often fluoresces pink, red, or orange under UV light.
Optical Properties
Refractive Index: 1.486 - 1.658; Birefringence: Very strong (0.172); Uniaxial negative. High birefringence can cause double refraction (doubling of images seen through clear specimens).
Hardness & Durability
Origin Region
Mexico (most common), Brazil, USA, and Canada. Found in sedimentary environments, limestone caves, and hydrothermal deposits.
Hardness & Durability
Mohs Hardness: 3 (Very soft); Toughness: Poor due to perfect cleavage. Highly sensitive to acids and prone to scratching from everyday dust (which contains silica/quartz).
Care & Maintenance
Clean only with warm soapy water and a soft cloth. Do not use ultrasonic cleaners or steamers. Avoid all acids (including vinegar/citrus), as they will dissolve the stone. Store separately to avoid scratches.
Rarity & Value
Common; Value is generally low, based on color saturation and size. Mass-produced as tumbled stones, spheres, and carvings. Rarely faceted due to extreme softness and cleavage.
Special Characteristics
Displays a characteristic 'waxy' texture when polished. Shows strong effervescence (bubbling) when in contact with dilute hydrochloric acid. Some specimens exhibit phantom growth layers.
Lore & History
Historically used as a source of lime and for building materials (limestone/marble). In crystal lore, orange calcite is associated with the Sacral Chakra, believed to enhance creativity, playfulness, and emotional healing.