mineral

Aragonite crystal cluster

Aragonite (CaCO₃), orthorhombic calcium carbonate

AI-generated identification · may be incorrect

Brown, radiating cluster of short prismatic crystals with vitreous to pearly luster; Mohs hardness 3.5–4, specific gravity about 2.9. Individual crystals are orthorhombic, though the cluster habit can resemble hexagonal forms.

Identified October 15, 2026More mineral →

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Physical properties

Formation & geological history

Forms in low-temperature hydrothermal veins, caves, hot springs, and sedimentary environments, often by precipitation from calcium-rich water. The specimen’s age and locality cannot be determined from the image.

Uses & applications

Collected as a mineral specimen; aragonite also occurs in shells and pearls and is a constituent of some limestones and other carbonate materials.

Geological facts

Aragonite and calcite have the same chemical formula but different crystal structures (polymorphs); aragonite is less stable at Earth’s surface and may convert to calcite over geological time.

Field identification & locations

The radiating brown crystals are consistent with aragonite, but visual identification alone is not definitive; a locality label or mineral tests would help. Common occurrences include Spain, Morocco, Austria, and the Czech Republic.