sedimentary

Crushed Limestone and Calcite

Calcium Carbonate (CaCO3)

AI-generated identification · may be incorrect

Hardness: 3 (Mohs scale); Color: ranges from grey, tan, to white; Luster: dull to vitreous; Crystal structure: Trigonal (often massive/granular); Cleavage: Rhombohedral (perfect)

Hardness: 3 (Mohs scale)
Color: ranges from grey, tan, to white
Luster: dull to vitreous

Identified April 8, 2026More sedimentary →

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Physical properties

Hardness: 3 (Mohs scale); Color: ranges from grey, tan, to white; Luster: dull to vitreous; Crystal structure: Trigonal (often massive/granular); Cleavage: Rhombohedral (perfect)

Formation & geological history

Formed in marine environments from the accumulation of shell, coral, and algal debris. These specific pieces are likely sourced from a local quarry and processed as aggregate (crushed stone).

Uses & applications

Used primarily in construction for road base, concrete production, drainage, and landscape ground cover. The larger white specimen on the right may be massive quartz or calcite quartz veins.

Geological facts

Limestone occupies about 10% of the total volume of all sedimentary rocks. It is highly reactive with acid, fizzing vigorously when in contact with dilute hydrochloric acid.

Field identification & locations

Identify by its light grey color, blocky fracture, and tendency to react with weak acids. It is ubiquitous in construction sites and riverbeds in limestone-heavy regions.