Sandstone (with potentially metamorphic or basaltic bands)

Physical Properties

Hardness: 6-7 (on Mohs scale); Color: Tan, brown, and grey-green; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific gravity: approx. 2.0-2.6

Formation & Geological History

Formed from the accumulation of sand-sized mineral particles or rock fragments. The smooth, rounded shape indicates it is a river or beach cobble that has undergone significant mechanical weathering and transport. The darker bands suggest varying mineral layers or minor contact metamorphism.

Uses & Applications

Used in construction, as road base, or for architectural accents. Naturally weathered pebbles like this are often used in landscaping and garden decoration.

Geological Facts

Sandstone accounts for about 20% of all sedimentary rocks on Earth. This specific specimen’s rounded edges tell a story of hydraulic transport over miles, likely in a stream or along a coast.

Field Identification & Locations

Identify by its gritty texture (feels like sandpaper) and visible layering. It is commonly found in riverbeds, canyons, and coastal areas. Collectors look for unique banding patterns.

Identified on: 4/15/2026

Mode: Standard