mineral

Botryoidal aragonite (cave calcite/aragonite formation)

Aragonite, CaCO₃; possibly mixed with calcite and iron-oxide staining

AI-generated identification · may be incorrect

Cream to tan, botryoidal and cauliflower-like crust with mammillary growths, porous cavities, and dull to pearly luster. Mohs hardness 3.5–4; orthorhombic aragonite has imperfect cleavage, specific gravity about 2.9–3.0, and effervesces in dilute hydrochloric acid.

Identified September 6, 2026More mineral →

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Physical properties

Formation & geological history

Forms when calcium-carbonate-rich groundwater precipitates in caves, cavities, springs, or fractures; iron oxides create brown coloration. The specimen’s exact age cannot be determined visually and may range from recent to Quaternary.

Uses & applications

Primarily a collector specimen; attractive pieces may be used decoratively, but aragonite is too soft and fragile for most jewelry or construction applications.

Geological facts

Botryoidal means rounded, grape-like aggregates produced by repeated mineral growth. Aragonite is metastable and can slowly transform into the more stable calcite under suitable conditions.

Field identification & locations

Identify by rounded carbonate growths, porous cave-like texture, low hardness, and acid fizz; distinguish from chalcedony by its stronger acid reaction and softness. Common in karst caves and hydrothermal cavities worldwide.