mineral

Aragonite Star Cluster

Aragonite (Calcium Carbonate, CaCO3)

Hardness: 3.5-4.0; Color: Red-brown, white, or colorless; Luster: Vitreous to resinous; Crystal structure: Orthorhombic (specifically pseudo-hexagonal twinning); Cleavage: Distinct; Specific Gravity: 2.9-3.0.

Hardness: 3
Color: Red-brown, white, or colorless
Luster: Vitreous to resinous

Identified March 20, 2026More mineral →

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Physical properties

Formation & geological history

Formed in low-temperature hydrothermal environments near the Earth's surface or as precipitates in sedimentary basins. These specific 'star clusters' typically form through cyclic twinning where several crystals grow out from a common center.

Uses & applications

Primarily used as metaphysical healing stones, decorative collector pieces, and minor sources of building materials or soil conditioners in powdered form.

Geological facts

Aragonite is a polymorph of Calcite, meaning they share the same chemistry but different structures. Over long geological time scales, aragonite is unstable at standard surface temperatures and will eventually recrystallize into calcite.

Field identification & locations

Identify by its 'sputnik' or 'star cluster' shape made of radiating prismatic crystals with flat hexagonal-like ends. Common locations include Morocco (the source of most red-brown clusters), Spain, and Mexico.

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