sedimentary

Agate

Silicon dioxide (SiO2)

Hardness of 6.5 to 7 on the Mohs scale, waxy luster, and exhibits distinct concentric banding of various colors.

Identified October 20, 2026More sedimentary →

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Physical properties

Hardness of 6.5 to 7 on the Mohs scale, waxy luster, and exhibits distinct concentric banding of various colors.

Forms by the deposition of silica from groundwater in cavities of igneous and sedimentary rocks over millions of years.

Widely used in jewelry, decorative ornaments, and precision instruments due to its durability and chemical resistance.

Ancient civilizations used agate for talismans and seals believing it could ward off storms and sickness.

Identified by its translucent appearance, waxy texture, and unique color bands; commonly found worldwide in volcanic rock cavities.

Fossil-bearing concretion, possibly containing a fossil shell or other organic inclusion

Calcareous concretion; exact fossil and host-rock composition are not identifiable from the image

Fossiliferous Sedimentary Rock

Sedimentary limestone with invertebrate fossil imprint

Sandstone or Siltstone

Arenite (if sandstone)

Sandstone

Arenite

Shale

Shale (clastic sedimentary rock)

Shale (or Mudstone/Siltstone)

Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)