sedimentary
Limestone
Calcium Carbonate (CaCO3)
AI-generated identification · may be incorrectMohs hardness: 3, Color: Tan to light brown/grey, Luster: Dull/Earthy, Grain size: Variable, Reacts with HCl acid.
- Luster
- Dull/Earthy, Grain size: Variable, Reacts with HCl acid
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Physical properties
Mohs hardness: 3, Color: Tan to light brown/grey, Luster: Dull/Earthy, Grain size: Variable, Reacts with HCl acid.
Formation & geological history
Formed primarily from the accumulation of shell, coral, algal, and fecal debris in marine environments. This specimen appears to be of the clastic or biogenic variety typical of coastal or lakebed deposits.
Uses & applications
Used extensively in construction (aggregate, cement), agriculture (soil conditioner), and as a base material for roads.
Geological facts
Limestone makes up about 10% of the total volume of all sedimentary rocks. It often contains fossils of prehistoric marine life which are hidden within its layers.
Field identification & locations
Can be identified in the field by its softness (scratched by a copper penny) and its effervescent reaction when exposed to a weak acid like vinegar or hydrochloric acid.
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