mineral

Calcite crystal cluster

Calcite (CaCO₃), likely a cleavable crystalline aggregate

AI-generated identification · may be incorrect

Pale honey, peach, and white translucent crystals with pearly to vitreous luster and prominent cleavage surfaces; Mohs hardness 3, trigonal crystal system, specific gravity about 2.71. The radiating, bladed form and weakly banded coloration are consistent with calcite, though aragonite or quartz cannot be excluded from…

Identified September 7, 2026More mineral →

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Physical properties

Formation & geological history

Typically forms from carbonate-rich hydrothermal fluids, cave waters, or sedimentary cavities; the specimen may be a vug coating or radiating vein growth. Calcite forms throughout geologic time, commonly in limestone and hydrothermal deposits.

Uses & applications

Used industrially for cement, lime, aggregate, and chemical production; transparent optical calcite is collectible. This irregular cluster is mainly a display specimen rather than jewelry material.

Geological facts

Calcite effervesces strongly with dilute hydrochloric acid or vinegar, though vinegar may react slowly. It shows excellent rhombohedral cleavage and can display double refraction through clear pieces.

Field identification & locations

Common worldwide in limestone regions and hydrothermal districts, including Mexico, the United States, China, Morocco, and Peru. Confirm with a copper-coin or steel scratch test and acid reaction; avoid damaging valuable specimens.