mineral

Polished banded calcite/aragonite tower

Calcite (CaCO₃), possibly aragonite (CaCO₃)

AI-generated identification · may be incorrect

Hardness 3 (calcite) or 3.5–4 (aragonite); peach, cream, and tan fibrous bands with silky to waxy luster. The elongated layered texture suggests botryoidal or stalactitic carbonate material that has been cut and polished.

Identified September 4, 2026More mineral →

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Physical properties

Formation & geological history

Likely formed by precipitation from mineral-rich groundwater in caves or hydrothermal cavities, commonly during the Cenozoic. Exact identification requires hardness, acid, and mineralogical testing.

Uses & applications

Used as a decorative carving, crystal tower, and collectible; softer than quartz, so it is unsuitable for durable jewelry or construction aggregate.

Geological facts

Calcite effervesces visibly in dilute hydrochloric acid, while aragonite has the same chemistry but a different orthorhombic crystal structure. The parallel “wood-grain” pattern may indicate fibrous aragonite or banded cave calcite.

Field identification & locations

Common sources include Mexico, Morocco, Spain, and China. Test an inconspicuous area: calcite scratches with a copper coin and reacts strongly with acid; avoid confusing it with satin spar gypsum, which is softer and does not fizz.