mineral

Calcite specimen

Calcite (calcium carbonate, CaCO₃), likely botryoidal or drusy calcite

AI-generated identification · may be incorrect

Pale greenish-white, translucent to opaque, with sparkling crystal faces and uneven/botryoidal texture; vitreous to pearly luster. Mohs hardness 3, perfect rhombohedral cleavage, trigonal crystal system, specific gravity about 2.71; effervesces strongly in dilute hydrochloric acid.

Identified August 10, 2026More mineral →

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Physical properties

Formation & geological history

Forms in limestone cavities, hydrothermal veins, caves, and evaporite environments through precipitation from carbonate-rich fluids. The specimen’s exact geological age cannot be determined from the image alone.

Uses & applications

Used in cement, lime, agricultural soil treatment, chemical manufacture, and as a decorative or collector mineral; attractive transparent varieties may be cut, though this piece is primarily a specimen.

Geological facts

Calcite is one of Earth’s most common minerals and commonly displays strong birefringence, producing double images through clear crystals. Its pale green color may result from trace impurities or inclusions.

Field identification & locations

Look for rhombohedral cleavage, low hardness, glassy sparkle, and acid reaction; distinguish it from quartz because calcite is much softer and cleaves readily. Common worldwide, including Mexico, the United States, Brazil, and China.