Sandstone (with Iron Staining)

Physical Properties

Hardness: 6-7 Mohs; Color: Tan to yellowish-brown with dark iron-oxide banding (Liesegang rings); Luster: Dull/Earthy; Structure: Granular/Clastic; Cleavage: None.

Formation & Geological History

Formed through the accumulation and cementation of sand-sized mineral grains or rock fragments, typically in river beds, deserts, or marine environments. The dark banding is caused by secondary precipitation of iron-rich fluids.

Uses & Applications

Used primarily as a construction material (dimension stone), in glass manufacturing if pure silica, or as a decorative landscaping rock.

Geological Facts

Sandstone makes up about 20-25% of all sedimentary rocks on Earth. The dark curvy lines visible on this specimen are often called 'Liesegang rings', which are secondary chemical precipitates formed during weathering.

Field Identification & Locations

Identify by its gritty texture (feels like sandpaper) and visible sand grains. Found globally in basins and coastal areas. Collectors value specimens with unique aesthetic banding.

Identified on: 5/3/2026

Mode: Standard