sedimentary

Quartz Pebble

Silicon Dioxide (SiO2)

Hardness of 7 on the Mohs scale, grayish-white color, vitreous luster, and conchoidal fracture without distinct cleavage.

Identified November 7, 2026More sedimentary →

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Physical properties

Hardness of 7 on the Mohs scale, grayish-white color, vitreous luster, and conchoidal fracture without distinct cleavage.

Formed through intense weathering and aqueous erosion of parent quartz-bearing rocks, smoothed over long periods in fluvial or marine environments.

Commonly collected as a natural curiosity, used in landscaping, and sometimes tumbled for decorative jewelry or crafts.

Quartz is one of the most abundant and durable minerals in Earth's continental crust, highly resistant to both chemical and mechanical weathering.

Easily identified by its high hardness which scratches glass and its smooth, rounded shape found predominantly in riverbeds and beaches.

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)