sedimentary
Coquina
Bioclastic Sedimentary Rock
AI-generated identification · may be incorrectHardness varies from 3 to 4 on the Mohs scale. Colors range from white to light tan or gray, featuring a dull luster and a porous, highly fragmented shell texture.
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Physical properties
Hardness varies from 3 to 4 on the Mohs scale. Colors range from white to light tan or gray, featuring a dull luster and a porous, highly fragmented shell texture.
Formation & geological history
Formed by the accumulation, cementation, and compaction of shell fragments and marine fossils in high-energy beach environments.
Uses & applications
Used primarily as a local building stone, in road base construction, and occasionally in coastal landscaping.
Geological facts
Famous for being used to construct the historic Castillo de San Marcos in St. Augustine, Florida. It effectively absorbed cannon fire without shattering.
Field identification & locations
Identified by its distinct mass of visible, loosely cemented mollusk shells and fossils; commonly found along tropical and subtropical coastlines.
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