sedimentary

Limestone (Weathered)

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale; Color: Grey, tan, or buff; Luster: Dull to earthy; Crystal structure: Trigonal (microcrystalline); Cleavage: None in massive form; Specific Gravity: 2.5-2.7

Hardness: 3 on Mohs scale
Color: Grey, tan, or buff
Luster: Dull to earthy

Identified May 5, 2026More sedimentary →

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Physical properties

Hardness: 3 on Mohs scale; Color: Grey, tan, or buff; Luster: Dull to earthy; Crystal structure: Trigonal (microcrystalline); Cleavage: None in massive form; Specific Gravity: 2.5-2.7

Formation & geological history

Formed through the accumulation of shell, coral, algal, and fecal debris in marine environments. This specimen shows significant physical weathering and surface pitting from exposure.

Uses & applications

Used primarily in construction as road base, concrete aggregate, and in the production of cement and lime. Also used for soil acidity neutralization in agriculture.

Geological facts

Limestone makes up about 10% of the total volume of all sedimentary rocks. It is the primary rock type found in karst landscapes, known for caves and sinkholes.

Field identification & locations

Identify in the field by its reaction (fizzing) when exposed to a drop of dilute hydrochloric acid. Commonly found in areas that were once prehistoric sea beds.