sedimentary

Grey Jasper (Tumbled Quartz variant)

Jasper (Silicon Dioxide, SiO2)

AI-generated identification · may be incorrect

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 March 25, 2026More sedimentary →

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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.