Sandstone (Quartzose Sandstone)

Physical Properties

Hardness: 6-7 on Mohs scale (for grains); Color: Tan, beige, or light grey; Luster: Dull/Earthy; Structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.2-2.8

Formation & Geological History

Formed through the accumulation and litification of sand-sized mineral grains or rock fragments. This specific rounded specimen (cobble) suggests high-energy aquatic transport in a riverbed or coastal environment which eroded it into an ellipsoidal shape.

Uses & Applications

Common building material, used in grindstones, decorative glass manufacture, and as an aquifer for groundwater or reservoir for petroleum.

Geological Facts

Sandstone is one of the most common sedimentary rocks on Earth. This specific shape is known as a 'river rock' or 'clast' that has undergone significant abrasion and attrition over time.

Field Identification & Locations

Identify in the field by its gritty texture (feeling like sandpaper) and visible sand grains. Found globally in basins, riverbeds, and beaches.

Identified on: 4/15/2026

Mode: Standard