mineral
Calcite
Calcium Carbonate (CaCO3)
Hardness: 3 (Mohs scale), Color: White/Colorless, Luster: Vitreous to pearly, Crystal structure: Trigonal (rhombohedral cleavage), Specific gravity: 2.71
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Physical properties
Hardness: 3 (Mohs scale), Color: White/Colorless, Luster: Vitreous to pearly, Crystal structure: Trigonal (rhombohedral cleavage), Specific gravity: 2.71
Formation & geological history
Commonly formed in sedimentary environments as a chemical precipitate from evaporation or accumulation of marine organisms Shells. It can also form in metamorphic (marble) and igneous rocks.
Uses & applications
Used in construction as a component of cement and mortar, in agriculture for soil treatment, as an abrasive, and in the optical industry for high-grade specimens.
Geological facts
Calcite exhibits double refraction; when you look through a clear crystal, images appear doubled. It is the primary constituent of limestone and marble.
Field identification & locations
Identify in the field by its rhombohedral cleavage (breaks into slanted cubes) and its rapid effervescence when exposed to cold dilute hydrochloric acid.
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Other mineral specimens
Sandstone (with potential mineral staining/concretions)
Arenite (SiO2 based)
sedimentary
Schist
Schist
Metamorphic
Epidote
Epidote | Ca2(Al2,Fe3+)(SiO4)(Si2O7)O(OH)
metamorphic
Gypsum (variety Selenite or Alabaster)
Calcium sulfate dihydrate (CaSO4·2H2O)
Mineral
Nephrite Jade
Nephrite
Mineral/Rock
Granite
Granite (Phaneritic intrusive igneous rock)
igneous