sedimentary
Limestone Cobble
Sedimentary Limestone (Calcium Carbonate, CaCO3)
Hardness: 3-4 (Mohs scale), Color: tan to gray, Luster: dull/earthy, Structure: fine-grained/micritic, Specific Gravity: approx. 2.5-2.7
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Physical properties
Hardness: 3-4 (Mohs scale), Color: tan to gray, Luster: dull/earthy, Structure: fine-grained/micritic, Specific Gravity: approx. 2.5-2.7
Formation & geological history
Formed in marine environments through the accumulation of shell, coral, algal, and fecal debris. These rocks can date back hundreds of millions of years and typically form in warm, shallow coastal waters.
Uses & applications
Used in the production of cement, as a building stone, crushed for road base, and in the chemical industry to neutralize acidity in soil and water.
Geological facts
Limestone makes up about 10% of the total volume of all sedimentary rocks. It is the primary parent rock for karst topography, including caves and sinkholes.
Field identification & locations
Identify in the field by its softness (it can be scratched by a steel nail) and its energetic reaction (fizzing) when exposed to a weak acid like vinegar or hydrochloric acid.
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