sedimentary
River Rock (Sandstone or Quartzite)
Clastic Sedimentary Rock / Quartzite
AI-generated identification · may be incorrectHardness: 6-7 (Mohs scale), Color: earthy tan to gray, Luster: dull/matte (pearly when wet), Crystal structure: granular, Cleavage: none, Specific gravity: 2.6-2.7
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Physical properties
Hardness: 6-7 (Mohs scale), Color: earthy tan to gray, Luster: dull/matte (pearly when wet), Crystal structure: granular, Cleavage: none, Specific gravity: 2.6-2.7
Formation & geological history
Formed through the accumulation of sand grains (quartz) under pressure in marine or desert environments, followed by rounding via water erosion in a riverbed or shoreline.
Uses & applications
Commonly used in landscaping, decorative ground cover, construction aggregate, and as a natural material for stone painting or meditation (worry stones).
Geological facts
The rounded shape indicates a high degree of maturity, meaning the rock has traveled a long distance from its original source, being tumbled and smoothed by water over thousands of years.
Field identification & locations
Identify by its smooth, rounded edges and granular texture. Found globally in active or ancient riverbeds, beaches, and glacial deposits. Low rarity but high utility for landscaping.
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