mineral

Cave (botryoidal) aragonite or calcite specimen

Aragonite (CaCO₃), possibly mixed with calcite and iron-oxide inclusions

AI-generated identification · may be incorrect

Typically hardness 3.5–4 for aragonite (calcite 3), vitreous to pearly luster, white to honey-brown coloration, translucent edges, and irregular botryoidal or radiating crystal growth. The brown color likely comes from iron oxides or organic impurities;…

Identified August 22, 2026More mineral →

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Physical properties

Formation & geological history

Forms when calcium-carbonate-rich groundwater precipitates in caves, cavities, springs, or hydrothermal veins; aragonite is generally metastable and may recrystallize to calcite over geological time. The specimen’s exact age and locality cannot be determined from the image.

Uses & applications

Used mainly as a mineral-collecting specimen; calcite and aragonite are important carbonate minerals but have limited direct industrial value in this form. Attractive pieces may be displayed or sold as lapidary specimens.

Geological facts

Aragonite and calcite share the same chemical formula but differ in crystal structure, making them polymorphs. Botryoidal surfaces resemble clusters of rounded droplets or coral-like growths.

Field identification & locations

Likely identification requires a hardness test, acid reaction, streak, and examination of crystal habits; avoid acid if preservation matters. Common sources include Spain, Morocco, Mexico, the United States, and many limestone cave regions.