Sandstone (Quartzite-rich Pebble)

Physical Properties

Hardness: 6-7 (Mohs scale); Color: Tan, beige, or off-white; Luster: Dull to earthy; Crystal Structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.2-2.8

Formation & Geological History

Formed from the accumulation and cementation of mineral particles or rock fragments, typically sand-sized quartz grains. This specimen appears as a water-worn river pebble, shaped by fluvial erosion over thousands of years.

Uses & Applications

Common sandstone is used in construction (building stone, flagstone) and glass manufacturing. Smooth pebbles like this are popular for landscaping, aquarium decor, and pocket stones.

Geological Facts

Sandstone accounts for about 20% of all sedimentary rocks on Earth. It often acts as a natural aquifer, storing groundwater or petroleum in its porous spaces.

Field Identification & Locations

Identify in the field by its gritty texture (feels like sandpaper) and rounded edges if found in or near water. It is extremely common in sedimentary basins and riverbeds worldwide.

Identified on: 4/19/2026

Mode: Standard