sedimentary
Limestone with Chert
Calcium Carbonate (CaCO3) with Silica (SiO2) inclusions
Hardness: 3 (limestone matrix) to 7 (chert nodules); Color: Grey, tan, and white; Luster: Dull to earthy; Structure: Biogenic or chemical sedimentary layering; Specific Gravity: 2.3-2.7
- Hardness
- 3 (limestone matrix) to 7 (chert nodules)
- Color
- Grey, tan, and white
- Luster
- Dull to earthy
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3 (limestone matrix) to 7 (chert nodules); Color: Grey, tan, and white; Luster: Dull to earthy; Structure: Biogenic or chemical sedimentary layering; Specific Gravity: 2.3-2.7
Formation & geological history
Formed in marine environments through the accumulation of shell, coral, and algal debris, often with secondary silica replacement forming chert nodules over millions of years.
Uses & applications
Construction material, production of cement, crushed stone for road base, and soil conditioner in agriculture.
Geological facts
Limestone is the primary source of lime used in making glass. It often contains fossils of ancient marine organisms that lived millions of years ago.
Field identification & locations
Identified by its grey color and reaction to dilute hydrochloric acid (it fizzes). Harder chert nodules within will scratch steel. Commonly found in karst landscapes and coastal cliffs.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite
sedimentary