sedimentary
Cannonball Concretion
Calcite-cemented sandstone concretion
AI-generated identification · may be incorrectHardness of 6-7, earthy brown to grey color, dull luster, amorphous granular crystal structure with no cleavage, and a high specific gravity due to dense cementation.
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Physical properties
Hardness of 6-7, earthy brown to grey color, dull luster, amorphous granular crystal structure with no cleavage, and a high specific gravity due to dense cementation.
Formation & geological history
Formed in shallow marine sedimentary layers where minerals precipitate around a nucleus, often during the Cenozoic or Mesozoic eras.
Uses & applications
Primarily collected as geological curiosities and natural display specimens.
Geological facts
These spherical structures often weather out of surrounding softer rock formations like sandstone cliffs, mimicking manufactured cannonballs.
Field identification & locations
Identified by their remarkably spherical or disc shape and harder composition than the host rock; commonly found in formations worldwide such as North Dakota and New Zealand.
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