sedimentary
Chert (Red Jasper variety)
Silicon Dioxide (SiO2)
AI-generated identification · may be incorrectHardness: 6.5-7 (Mohs scale); Color: Reddish-brown with white inclusions; Luster: Vitreous to waxy; Structure: Cryptocrystalline; Fracture: Conchoidal; Specific gravity: 2.6-2.7
- Hardness
- 6
- Color
- Reddish-brown with white inclusions
- Luster
- Vitreous to waxy
Identified More sedimentary →
Explore Chert (Red Jasper variety) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 (Mohs scale); Color: Reddish-brown with white inclusions; Luster: Vitreous to waxy; Structure: Cryptocrystalline; Fracture: Conchoidal; Specific gravity: 2.6-2.7
Formation & geological history
Formed through the accumulation of silica-rich microfossils or chemical precipitation in sedimentary basins. The red color is caused by iron oxide (hematite) impurities.
Uses & applications
Historically used for stone tools and arrowheads; currently used in lapidary work, jewelry, and as decorative stone in landscaping.
Geological facts
Chert is so hard it can strike sparks from steel, leading to its widespread use as gunflints in early firearms.
Field identification & locations
Identify by its 'glassy' conchoidal fracture patterns and inability to be scratched by a steel knife. Often found in riverbeds or as nodules within limestone or chalk formations.
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