sedimentary
Sandstone Cobble
Arenite (primarily Quartz Arenite)
Hardness 6.5-7 (individual grains), Color: Tan to yellow-brown (iron-stained), Luster: Dull/Earthy, Texture: Clastic with visible sand grains, Cleavage: None
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Physical properties
Hardness 6.5-7 (individual grains), Color: Tan to yellow-brown (iron-stained), Luster: Dull/Earthy, Texture: Clastic with visible sand grains, Cleavage: None
Formation & geological history
Formed through the accumulation and cementation of sand-sized mineral grains, typically in riverbeds, beaches, or desert environments. This specimen is well-rounded, indicating significant transport by water.
Uses & applications
Crushed for construction aggregate, used in glass making if high purity, or as a decorative landscaping stone.
Geological facts
This particular stone is a 'river rock,' having been smoothed and rounded by the abrasive action of water and other sediment over thousands of years.
Field identification & locations
Identify by its 'sandpaper' feel and visible layers or banding. Commonly found in riverbeds and glacial deposits. Collectors value unique shapes or internal fossils.
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