Sandstone (Quartzose Pebble)

Physical Properties

Hardness: 6-7 on Mohs scale (due to silica content); Color: Tan, beige, or light grey; Luster: Dull/Earthy; Crystal Structure: Clastic (grainy texture); Cleavage: None; Specific Gravity: Approx 2.2-2.8.

Formation & Geological History

Formed through the accumulation and cementation of sand-sized mineral grains or rock fragments over millions of years, typically in riverbeds, beaches, or deserts. This pebble has been rounded by water erosion.

Uses & Applications

Commonly used as construction aggregate, in glass manufacturing, for architectural stone, or as landscape gravel. Small pebbles like this are often used in home decor or aquarium substrates.

Geological Facts

Sandstone accounts for roughly 20 to 25 percent of all sedimentary rocks in the earth's crust. Most sandstones are composed of quartz or feldspar because these are the most common minerals in the Earth's crust.

Field Identification & Locations

Identify in the field by its gritty texture (feels like sandpaper) and visible grains. Often found in dry riverbeds or coastal environments. Collectors look for unique banding or fossil inclusions.

Identified on: 4/16/2026

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