sedimentary
Limestone ( weathered ) / Chert Nodular Rock
Sedimentary rock (primarily Calcium Carbonate, CaCO3, with Microcrystalline Quartz, SiO2)
Hardness: 3 for limestone matrix, 7 for chert nodules. Color: Buff, light brown, tan to yellowish. Luster: Dull, earthy. Structure: Fine-grained, non-crystalline appearance, highly weathered exterior. Specific gravity: 2.5 - 2.7.
- Hardness
- 3 for limestone matrix, 7 for chert nodules
- Color
- Buff, light brown, tan to yellowish
- Luster
- Dull, earthy
Identified More sedimentary →
Explore Limestone ( weathered ) / Chert Nodular Rock in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 3 for limestone matrix, 7 for chert nodules. Color: Buff, light brown, tan to yellowish. Luster: Dull, earthy. Structure: Fine-grained, non-crystalline appearance, highly weathered exterior. Specific gravity: 2.5 - 2.7.
Formation & geological history
Formed in shallow, warm marine environments through the accumulation and compaction of organic debris or chemical precipitation of calcium carbonate, often containing chert nodules or silica inclusions. Weathering has given it a rough, buff-colored outer rind.
Uses & applications
Commonly used in construction, crushed stone aggregate, road base, soil conditioning (lime), cement manufacturing, and building material.
Geological facts
Weathered limestone and chert often form nodules that can host internal hollows or geodes. Limestone makes up about 10% of the total volume of all sedimentary rocks globally.
Field identification & locations
Identify in the field by checking if it effervesces (fizzes) with dilute hydrochloric acid. It can often be scratched with a steel nail if pure limestone, or resist scratching if silicified/cherty. Found abundantly worldwide in sedimentary rock basins.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale
Argillaceous sedimentary rock
sedimentary
Mudstone
Argillite / Siliciclastic sedimentary rock
sedimentary