sedimentary

Sandstone with Iron Oxide Staining

Clastic sedimentary rock (primarily SiO2 with Fe2O3 staining)

Hardness: 6-7 (on sand grains); Color: Grayish-white base with reddish-brown/orange stains; Luster: Dull/Earthy; Crystal Structure: Clastic granular texture; Cleavage: None (grains are cemented); Specific Gravity: 2.2-2.8

Hardness: 6-7 (on sand grains)
Color: Grayish-white base with reddish-brown/orange stains
Luster: Dull/Earthy

Identified June 9, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from the lithification of sand-sized mineral particles or rock fragments, typically in desert, river, or coastal environments. The reddish staining occurs through the oxidation of iron-rich minerals (chemical weathering) over thousands to millions of years.

Uses & applications

Used widely in construction as a building material, in glass manufacturing if pure quartz, and commonly used as decorative landscaping stones.

Geological facts

Sandstone makes up about 20% to 25% of all sedimentary rocks on Earth. The red color suggests the presence of hematite or limonite, often referred to as 'desert varnish' when on the surface.

Field identification & locations

Identify by its gritty texture (feels like sandpaper) and visible sand grains. It is extremely common in sedimentary basins and arid regions. Collectors look for unique banding patterns known as Liesegang rings.

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