sedimentary

Agate

Silicon Dioxide (Chalcedony), SiO2

Hardness of 6.5 to 7 on the Mohs scale, waxy luster, conchoidal fracture, and distinct banded or concentric patterns in various colors.

Identified November 12, 2026More sedimentary →

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

Physical properties

Hardness of 6.5 to 7 on the Mohs scale, waxy luster, conchoidal fracture, and distinct banded or concentric patterns in various colors.

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

Commonly used in making jewelry, ornamental carvings, decorative objects, and precision instruments like mortars and pestles.

Agate was highly prized in ancient civilizations like Egypt and Greece for amulets, seals, and healing talismans.

Identified by its waxy luster, hardness that scratches glass, and characteristic translucent banding. 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

Sandstone or Siltstone

Arenite (if sandstone)

Fossiliferous Sedimentary Rock

Sedimentary limestone with invertebrate fossil imprint

Sandstone

Arenite

Shale

Shale (clastic sedimentary rock)

Shale (or Mudstone/Siltstone)

Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)