Sandstone

Physical Properties

Hardness: 6-7 (Mohs scale); Color: Tan, yellow, and reddish-brown bands (iron oxide staining); 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 mineral particles or rock fragments (sand) over millions of years. This specimen shows distinct bedding or banding, likely stained by iron oxides (hematite/limonite) during diagenesis.

Uses & Applications

Used in building construction, paving, grindstones, and as a reservoir rock for oil and gas. In landscaping, it is used for decorative garden paths and rock walls.

Geological Facts

Sandstone makes up about 10-20% of the Earth's sedimentary rocks. The famous 'Wave' formation in Arizona is a classic example of cross-bedded sandstone.

Field Identification & Locations

Identify in the field by its gritty, abrasive texture (like sandpaper) and visible layers. Commonly found in riverbeds, deserts, and coastal areas. Collectors look for unique banding patterns like 'picture sandstone'.

Identified on: 4/24/2026

Mode: Standard