sedimentary
Grey Jasper (Tumbled Quartz variant)
Jasper (Silicon Dioxide, SiO2)
Hardness: 6.5-7 (Mohs scale); Color: Opaque grey; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91
- Hardness
- 6
- Color
- Opaque grey
- Luster
- Vitreous to waxy
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 (Mohs scale); Color: Opaque grey; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91
Formation & geological history
Formed from the deposition of silica from water or volcanic ash, occurring in sedimentary rocks or as hydrothermal vein fillings. Often found in Precambrian to Tertiary formations.
Uses & applications
Used primarily for balancing stones, jewelry (pendants/beads), home decor, and lapidary practice. Historically used for making tools due to its toughness.
Geological facts
Jasper is an impure variety of silica; the grey coloration is often due to the inclusion of clay minerals or carbonaceous material rather than iron oxides found in red variants.
Field identification & locations
Identify by its extreme hardness (cannot be scratched by a steel knife) and its smooth, waxy feel when tumbled. Commonly found in riverbeds or coastal areas in Oregon, India, and Brazil.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone (Quartz-rich)
Arenite (SiO2)
sedimentary
Sandstone (with man-made markings)
Arenite (composed primarily of Quartz, SiO2)
sedimentary