Sandstone (Quartz-rich)

Physical Properties

Hardness: 6-7 (Mohs scale); Color: Pale greyish-green; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific gravity: 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. This specimen shows significant water-worn redondeing, likely from a river or beach environment.

Uses & Applications

Commonly used in construction, as a building stone (freestone), and sometimes as a source of silica for glass making. In this small, rounded form, it is primarily a decorative or pocket stone.

Geological Facts

Sandstone accounts for roughly 20% of all sedimentary rocks on Earth. The 'greenish' tint in some specimens can be caused by the presence of minerals like glauconite or chlorite.

Field Identification & Locations

Identify in the field by its gritty, sandpaper-like texture and visible sand grains. It is commonly found in sedimentary basins and along riverbeds. For collectors, look for cross-bedding or fossils within larger blocks.

Identified on: 4/21/2026

Mode: Standard