sedimentary

Crushed Limestone

Calcium Carbonate (CaCO3)

Hardness: 3 on Mohs scale; Color: White to light grey; Luster: Dull to earthy; Crystal structure: Trigonal/Hexagonal; Cleavage: Perfect rhombohedral in calcite form; Specific gravity: 2.7.

Hardness: 3 on Mohs scale
Color: White to light grey
Luster: Dull to earthy

Identified June 2, 2026More sedimentary →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Hardness: 3 on Mohs scale; Color: White to light grey; Luster: Dull to earthy; Crystal structure: Trigonal/Hexagonal; Cleavage: Perfect rhombohedral in calcite form; Specific gravity: 2.7.

Formation & geological history

Formed in marine environments through the accumulation of shell, coral, algal, and fecal debris. It can also form via chemical precipitation from ocean or lake water rich in calcium carbonate.

Uses & applications

Widely used in construction for road base, aggregate in concrete, and flux in steel production. Also used as a soil conditioner in agriculture and as a filler in paper and plastics.

Geological facts

Limestone covers about 10% of the total surface area of all sedimentary rocks. It is also the primary source of biological fossils found in the geologic record.

Field identification & locations

Identify in the field by its effervescence (bubbling) when touched with dilute hydrochloric acid. It is commonly found in ancient seabed regions and karst landscapes.