sedimentary
Bivalve Fossil (Shell Fragment)
Class Bivalvia (Calcium Carbonate - CaCO3)
Hardness: 3-3.5 on Mohs scale; Color: Chalky white to tan; Luster: Dull or pearly; Structure: Fragment of a hinged shell with distinct concentric growth lines; Specific Gravity: Approx 2.7.
- Hardness
- 3-3
- Color
- Chalky white to tan
- Luster
- Dull or pearly
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Physical properties
Hardness: 3-3.5 on Mohs scale; Color: Chalky white to tan; Luster: Dull or pearly; Structure: Fragment of a hinged shell with distinct concentric growth lines; Specific Gravity: Approx 2.7.
Formation & geological history
Formed through the process of fossilization where the calcium carbonate shell of a marine mollusk was preserved in sedimentary layers. These specimens can range from the Cambrian period to the Holocene.
Uses & applications
Primarily used for educational purposes, scientific study of paleoenvironments, or as decorative items in small rock collections.
Geological facts
Bivalves include modern clams, oysters, and mussels. Their shells are made of two parts (valves) that are typically symmetrical. They are excellent environmental indicators for ancient water depths and temperatures.
Field identification & locations
Identify in the field by looking for fan-shaped or concentric ridges on flat, curved white rock fragments in limestone or shale beds. Common in coastal regions or areas that were historically undersea.
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