Calcite (Speleothem formation)
Calcite · Mineral Specimen / Decorative Stone
Crystal System
Trigonal, forming massive, stalactitic, or crystalline aggregates
Mineral Group
Carbonates
Chemical Formula
CaCO3
Formation Process
Sedimentary / Chemical precipitation from mineral-saturated groundwater dripping or flowing inside caves
About This Crystal
The image shows the interior of a limestone cave featuring extensive speleothem formations, including stalactites hanging from the ceiling and stalagmites rising from the floor. The surfaces are composed of crystalline calcium carbonate with earthy, brownish, and greyish tones, displaying a dull to vitreous luster where wet.
Physical Characteristics
Color ranges from white to grey and brown due to impurities; white streak; perfect rhombohedral cleavage in three directions; conchoidal to uneven fracture; specific gravity of approximately 2.71; brittle tenacity; frequently exhibits strong fluorescence under UV light.
Optical Properties
Uniaxial negative with very strong birefringence (double refraction), giving a distinct double image when viewed through transparent rhombs.
Hardness & Durability
Origin Region
Found worldwide in limestone caves and karst topography systems
Hardness & Durability
Mohs hardness of 3, making it soft and easily scratched. Poor toughness due to perfect cleavage, unsuitable for most everyday jewelry wear.
Care & Maintenance
Clean with a soft dry cloth or gentle dusting. Avoid acids (like vinegar or lemon juice) which will fizz and dissolve the mineral. Keep away from harsh chemicals and excess moisture.
Rarity & Value
Common mineral, though complex or large cave formations are protected natural resources. Value varies widely from inexpensive tumbled stones to valuable large mineral specimens.
Special Characteristics
Strong phosphorescence or fluorescence under ultraviolet light in many varieties, and notable double refraction in transparent crystal specimens.
Lore & History
Historically used in architecture and construction as limestone and marble. In metaphysical traditions, calcite is regarded as a powerful amplifier and cleanser of energy, traditionally associated with the balancing of emotional states and spiritual grounding.