sedimentary

Limestone (Fossiliferous)

Calcium Carbonate (CaCO3)

AI-generated identification · may be incorrect

Hardness: 3 on Mohs scale; Color: Tan, beige, light gray; Luster: Dull/Earthy; Structure: Clastic or organic; Specific Gravity: 2.3-2.7. Shows visible shell fragments and a rugged, weathered texture.

Hardness: 3 on Mohs scale
Color: Tan, beige, light gray
Luster: Dull/Earthy

Identified July 15, 2026More sedimentary →

Explore Limestone (Fossiliferous) in the encyclopedia →

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: Tan, beige, light gray; Luster: Dull/Earthy; Structure: Clastic or organic; Specific Gravity: 2.3-2.7. Shows visible shell fragments and a rugged, weathered texture.

Formation & geological history

Formed in warm, shallow marine environments from the accumulation of shell, coral, algal, and fecal debris. These sediments are lithified over millions of years through pressure and chemical precipitation.

Uses & applications

Used in construction as a building material, as aggregate for road base, in the manufacture of cement, and as a soil conditioner (lime) 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' topography, where it can dissolve over time to form massive cave systems.

Field identification & locations

Identify in the field by applying a drop of dilute hydrochloric acid; limestone will fizz (effervesce) as it releases carbon dioxide. Check for visible marine fossils or a gritty, sandy feel.