fossil
Sea Shell (Mollusk Shell)
Calcium Carbonate (Aragonite/Calcite)
Hardness of 3.5-4 on the Mohs scale, vitreous to pearly luster, orthorhombic or trigonal crystal system, white to patterned brown/tan exterior colors.
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Physical properties
Hardness of 3.5-4 on the Mohs scale, vitreous to pearly luster, orthorhombic or trigonal crystal system, white to patterned brown/tan exterior colors.
Formation & geological history
Formed biologically by marine mollusks secreting calcium carbonate from seawater to build protective exoskeletons, often preserved in sedimentary marine deposits over geological time.
Uses & applications
Used in decorative items, jewelry, shellcraft, and as collectible specimens.
Geological facts
Shells are frequently composed of nacre (mother-of-pearl) which has a unique iridescent optical property due to microscopic structure.
Field identification & locations
Found worldwide along coastal beaches and in marine sedimentary rock layers; identified by its organic shape and calcium carbonate composition.
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