sedimentary

Arkosic Sandstone

Arkose

AI-generated identification · may be incorrect

Hardness: 6-7 (on Mohs scale); Color: Pinkish-red to tan due to high feldspar content; Luster: Dull/Earthy; Crystal structure: Clastic (grainy texture); Cleavage: None (fractures across grains); Specific gravity: 2.5–2.7.

Hardness: 6-7 (on Mohs scale)
Color: Pinkish-red to tan due to high feldspar content
Luster: Dull/Earthy

Identified April 11, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from the rapid erosion and deposition of granitic rock, preventing the feldspar from weathering into clay. Usually deposited in alluvial fans or rift basins during periods of high tectonic activity.

Uses & applications

Used primarily as decorative building stone, in high-end masonry, and as a source for understanding ancient tectonic environments and mountain-building events.

Geological facts

Arkose is often referred to as 'dirty sandstone' because it contains at least 25% feldspar, unlike pure quartz sandstone. Ayers Rock (Uluru) in Australia is largely composed of arkosic sandstone.

Field identification & locations

Identify in the field by its gritty 'sandpaper' texture and distinctive pink or salmon color. Look for visible crystalline grains of quartz and angular feldspar. Common in mountainous regions with granite outcrops.