sedimentary or mineral
Red Jasper or Ironstone concretion
SiO2 or Fe2O3
AI-generated identification · may be incorrectRed to reddish-brown color, opaque, Mohs hardness 5.5-7 depending on composition, dull to somewhat earthy luster, compact and lumpy or nodular surface.
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Physical properties
Red to reddish-brown color, opaque, Mohs hardness 5.5-7 depending on composition, dull to somewhat earthy luster, compact and lumpy or nodular surface.
Formation & geological history
Formed through sedimentary processes, often as a concretion in sedimentary rocks or from silica-rich fluids precipitating in rock cavities. The red color is typically due to iron oxide inclusions.
Uses & applications
Commonly collected as river rocks or tumbling rough. Sometimes used for lapidary work if solid enough.
Geological facts
Red jasper and ironstone concretions are very common finds in dry riverbeds and desert environments.
Field identification & locations
Identify by its opaque red color, hardness (cannot be easily scratched by a steel nail if jasper), and irregular, somewhat rounded shape from weathering. Generally found worldwide.
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