mineral
Seashell Fragment
Calcium Carbonate (CaCO3) in the form of Aragonite or Calcite
Hardness: 3.0-4.0 (Mohs); Color: White, cream, or beige; Luster: Pearly to dull; Structure: Biogenic microcrystalline; Cleavage: None (conchoidal fracture)
- Hardness
- 3
- Color
- White, cream, or beige
- Luster
- Pearly to dull
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Physical properties
Hardness: 3.0-4.0 (Mohs); Color: White, cream, or beige; Luster: Pearly to dull; Structure: Biogenic microcrystalline; Cleavage: None (conchoidal fracture)
Formation & geological history
Formed by marine organisms (mollusks) using minerals extracted from seawater. Geological age can range from modern (Holocene) to millions of years old if fossilized.
Uses & applications
Used in the production of lime, as a source of calcium in animal feed, for beach restoration, and occasionally in jewelry or decorative crafts.
Geological facts
Shells are considered biomineralized materials. They are mostly composed of aragonite, a polymorph of calcium carbonate that is stronger than simple calcite crystals.
Field identification & locations
Identify by its curved form, growth rings, and characteristic chalky texture when scratched. Found in coastal regions and sedimentary rock layers.
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