Sandstone (Quartzose)

Physical Properties

Hardness: 6.5-7 (individual grains); Color: Brownish-red to tan; Luster: Dull/Earthy; Crystal Structure: Clastic/Granular; Cleavage: None; Specific Gravity: 2.2-2.8

Formation & Geological History

Formed through the accumulation and cementation of sand-sized mineral grains, typically quartz. Water or wind deposits these grains in layers which are then compacted and lithified over millions of years.

Uses & Applications

Used primarily as road base, construction material, decorative landscaping, and occasionally for grindstones or architectural stone.

Geological Facts

Sandstone contains about 20-25% of the total sedimentary rock on earth. It is often porous enough to act as a significant aquifer for groundwater or a reservoir for petroleum and natural gas.

Field Identification & Locations

Identify by its 'sandpaper' texture and visible small grains. It is commonly found in riverbeds, beaches, and desert environments. It will not fizz with acid unless it has a calcium carbonate cement.

Identified on: 4/20/2026

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