sedimentary
Jasper / Chert (Iron-stained)
Microcrystalline Quartz (SiO2)
AI-generated identification · may be incorrectHardness 6.5-7 on Mohs scale; dull to waxy luster; conchoidal fracture; brown, tan, and dark red hues due to iron oxide inclusions.
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Physical properties
Hardness 6.5-7 on Mohs scale; dull to waxy luster; conchoidal fracture; brown, tan, and dark red hues due to iron oxide inclusions.
Formation & geological history
Forms via precipitation of silica in sedimentary environments or hydrothermal replacement of carbonates, commonly from Precambrian to Cenozoic eras.
Uses & applications
Commonly used for lapidary work, cabochons, decorative landscape stone, and historically for flintknapping tools.
Geological facts
Jasper gets its varied opaque colors from trace mineral impurities, with iron oxides creating rich red and brown tones.
Field identification & locations
Identify in the field by its smooth, waxy feel, sharp conchoidal edges when fractured, and inability to be scratched by a steel nail.
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