Sandstone (Banded)

Physical Properties

Hardness: 6-7 (Mohs scale); Color: Tan, beige, and reddish-brown bands; Luster: Dull/Earthy; Crystal structure: Granular/Clastic; Cleavage: None; Specific Gravity: 2.2-2.8.

Formation & Geological History

Formed through the accumulation and lithification of sand-sized silicate grains. The bands are caused by variations in mineral content or grain size during deposition in ancient riverbeds, deserts, or coastal environments. Often millions of years old.

Uses & Applications

Commonly used as a building material, decorative stone, for paving, and as an industrial source of silica for glassmaking.

Geological Facts

The red bands are typically caused by iron oxide (hematite) staining the quartz grains. Over 25% of all sedimentary rocks on Earth are sandstones.

Field Identification & Locations

Identify in the field by its gritty 'sandpaper' texture and visible layering (stratification). Found globally in sedimentary basins, canyons, and riverbanks.

Identified on: 4/15/2026

Mode: Standard