Sandstone (likely River-tumbled Picture Sandstone)

Physical Properties

Hardness: 6-7 Mohs; Color: Tan, beige, and reddish-brown bands; Luster: Dull/Earthy; Crystal structure: Clastic (granular texture); Cleavage: None/Conchoidal on grains; Specific gravity: 2.2-2.8

Formation & Geological History

Formed through the accumulation and cementation of sand-sized mineral grains, typically quartz and feldspar. The distinct banding (Liesegang rings) occurs as mineral-rich groundwater precipitates iron oxides into the porous rock over millions of years.

Uses & Applications

Used in landscaping, as a building material, and for decorative lapidary work. Polished varieties are frequent in the crystal/metaphysical market.

Geological Facts

Sandstone makes up about 20% of all sedimentary rocks on Earth. The rhythmic banding seen here is often mistaken for wood grain or petrified wood, a phenomenon known as 'picture sandstone'.

Field Identification & Locations

Identify in the field by its gritty texture (feels like sandpaper) and visible bedding planes. Common in desert environments, riverbeds, and ancient basins. It is a vital reservoir rock for water and petroleum.

Identified on: 4/22/2026

Mode: Standard