mineral

Aragonite (Sputnik habit)

Aragonite (Calcium Carbonate, CaCO3)

Hardness: 3.5-4.0 Mohs; Color: Pale brown, orange, or reddish-brown; Luster: Vitreous to resinous; Crystal structure: Orthorhombic (pseudo-hexagonal twins); Specific gravity: 2.9-3.0.

Hardness: 3
Color: Pale brown, orange, or reddish-brown
Luster: Vitreous to resinous

Identified April 5, 2026More mineral →

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Physical properties

Hardness: 3.5-4.0 Mohs; Color: Pale brown, orange, or reddish-brown; Luster: Vitreous to resinous; Crystal structure: Orthorhombic (pseudo-hexagonal twins); Specific gravity: 2.9-3.0.

Formation & geological history

Formed through low-temperature sedimentary processes, particularly in oxidized zones of ore deposits or as precipitates from hot springs (evaporative environment). It is a polymorph of calcite.

Uses & applications

Primarily used as decorative display specimens for collectors and in holistic practices. It has minor industrial use in soil pH balancing and as an aquarium substrate.

Geological facts

This specific radiating form is nicknamed 'Sputnik' after the Russian satellite. Over time, aragonite is metastable at surface temperatures and may slowly convert to calcite.

Field identification & locations

Identified by its distinctive hexagonal prism clusters and 'twinned' radiating shapes. Commonly found in Morocco (notably the Tazouta area). It will effervesce (fizz) when exposed to weak acids like vinegar.

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