Rock Identifier
Limestone with Fossil Inclusion (Calcium Carbonate (CaCO3) - Bioclastic Limestone) — sedimentary
sedimentary

Limestone with Fossil Inclusion

Calcium Carbonate (CaCO3) - Bioclastic Limestone

Hardness: 3-4 (Mohs); Color: tan, grey, cream; Luster: dull to earthy; Structure: massive with visible bioclasts; Reacts strongly with dilute hydrochloric acid.

Hardness
3-4 (Mohs)
Color
tan, grey, cream
Luster
dull to earthy
Identified More sedimentary
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Physical properties

Hardness: 3-4 (Mohs); Color: tan, grey, cream; Luster: dull to earthy; Structure: massive with visible bioclasts; Reacts strongly with dilute hydrochloric acid.

Formation & geological history

Formed in shallow marine environments from the accumulation of skeletal fragments of marine organisms like coral, forams, and mollusks over millions of years.

Uses & applications

Used extensively in construction (aggregate, cement), architecture (building stone), and as a soil conditioner in agriculture.

Geological facts

Limestone makes up about 10% of the total volume of all sedimentary rocks on Earth. This specimen shows a circular fossil impression, likely a bivalve or a weathered cephalopod section.

Field identification & locations

Identify in the field by checking for biological patterns or shells and performing an acid fizz test. Commonly found in massive beds across ancient seabed locations.