mineral

Aragonite Star Cluster

Aragonite (Calcium Carbonate, CaCO3)

Hardness: 3.5-4.0; Color: Pale honey to reddish-brown; Luster: Vitreous to resinous; Crystal structure: Orthorhombic (cyclic twinning); Cleavage: Distinct in one direction; Specific gravity: 2.95.

Hardness: 3
Color: Pale honey to reddish-brown
Luster: Vitreous to resinous

Identified March 20, 2026More mineral →

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Physical properties

Hardness: 3.5-4.0; Color: Pale honey to reddish-brown; Luster: Vitreous to resinous; Crystal structure: Orthorhombic (cyclic twinning); Cleavage: Distinct in one direction; Specific gravity: 2.95.

Formation & geological history

Formed through low-temperature hydrothermal activity or in sedimentary environments as an evaporite. These clusters specifically grow through cyclic twinning where multiple crystals radiate from a central point.

Uses & applications

Primarily used as decorative display specimens, for geological study, and in the metaphysical community. In industry, aragonite is used in cement and as a source of calcium.

Geological facts

Aragonite is chemically identical to calcite (polymorphs), but it has a different crystalline structure. It is the primary material in the shells of mollusks and the skeleton of corals.

Field identification & locations

Identify by its 'sputnik' or star-like radiating appearance with hexagonal-looking prisms. Common locations include Morocco (Sefrou region), Spain, and Mexico.

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