sedimentary
Brown Jasper / Chert
Microcrystalline Quartz (SiO2)
AI-generated identification · may be incorrectMohs hardness of 6.5-7; waxy to vitreous luster when wet or polished; cryptocrystalline structure; brownish-yellow to dark yellowish-brown color with internal micro-fractures and mottling; conchoidal fracture.
Identified More sedimentary →
Explore Brown Jasper / Chert in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Mohs hardness of 6.5-7; waxy to vitreous luster when wet or polished; cryptocrystalline structure; brownish-yellow to dark yellowish-brown color with internal micro-fractures and mottling; conchoidal fracture.
Formation & geological history
Formed through the precipitation of silica-rich solutions or the recrystallization of radiolarian/diatomaceous ooze in marine or sedimentary environments.
Uses & applications
Used in lapidary arts, tumbled rock collecting, decorative crafts, and historical tool-making (flint knapping).
Geological facts
Jasper and chert are opaque forms of microcrystalline quartz; the distinct brown hues are usually caused by iron oxide impurities such as goethite or limonite.
Field identification & locations
Identified by its smoothness, hardness (will scratch glass), conchoidal fracture, and opaque brownish coloration. Commonly found in riverbeds, gravel pits, and shoreline beaches.
More like this
Other sedimentary specimens
Fossiliferous Sedimentary Rock
Sedimentary limestone with invertebrate fossil imprint
fossil
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite
sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Shale
Shale (clastic sedimentary rock)
sedimentary
Shale (or Mudstone/Siltstone)
Sedimentary Mudrock (SiO2, Al2O3 base with clay minerals)
sedimentary