sedimentary

Sandstone (Ferruginous)

Arenite (Fe-rich SiO2)

Hardness: 6-7 (Mohs); Color: Tan, yellow-orange, or brown with red oxidation; Luster: Dull/Earthy; Crystal structure: Clastic (grainy); Cleavage: None; Specific gravity: 2.2-2.8

Hardness: 6-7 (Mohs)
Color: Tan, yellow-orange, or brown with red oxidation
Luster: Dull/Earthy

Identified April 6, 2026More sedimentary →

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Physical properties

Hardness: 6-7 (Mohs); Color: Tan, yellow-orange, or brown with red oxidation; Luster: Dull/Earthy; Crystal structure: Clastic (grainy); Cleavage: None; Specific gravity: 2.2-2.8

Formation & geological history

Formed through the accumulation and cementation of sand-sized mineral grains or rock fragments. The orange/red coloring indicates the presence of iron oxide (hematite or limonite) that precipitated between the grains as a natural cement.

Uses & applications

Used primarily in building construction as a paving or tile material. Highly weather-resistant specimens are used for monuments and landscaping.

Geological facts

Sandstone is one of the most common sedimentary rocks on Earth. This specific specimen appears to be a stream-rounded cobble, meaning its smooth surface was shaped by water transport over a long period.

Field identification & locations

Identify by its gritty, abrasive feel (like sandpaper). It is commonly found in riverbeds, canyons, and coastal areas. Look for visible sand grains and layering (bedding planes).