sedimentary
Jasper
Silicon dioxide (SiO2) with impurities, microcrystalline quartz
Hardness: 6.5-7 on the Mohs scale, Color: Brown, yellow, red, green, or multicolored, Luster: Vitreous to dull, Crystal structure: Trigonal (microcrystalline/cryptocrystalline), Cleavage: None (exhibits conchoidal fracture), Specific gravity: 2.55-2.70
- Hardness
- 6
Identified More sedimentary →
Explore Jasper in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7 on the Mohs scale, Color: Brown, yellow, red, green, or multicolored, Luster: Vitreous to dull, Crystal structure: Trigonal (microcrystalline/cryptocrystalline), Cleavage: None (exhibits conchoidal fracture), Specific gravity: 2.55-2.70
Formation & geological history
Formed by the precipitation of silica-rich fluids in sedimentary environments, often involving volcanic ash or hydrothermal activity, over millions of years
Uses & applications
Used for ornamental objects, cabochons in jewelry, carvings, and as a collector specimen
Geological facts
Jasper has been used since ancient times for talismans, seals, and jewelry due to its toughness and ability to take a fine polish
Field identification & locations
Can be identified in the field by its waxy to dull luster, smooth water-worn surface (if found in riverbeds), conchoidal fracture, and inability to be scratched by a steel knife. Commonly found in stream gravels and sedimentary rock formations worldwide
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Quartz pebble
Silicon dioxide (SiO2)
sedimentary
Generic Pebble / Rock Fragment
Lithic fragment / Weathered rock
sedimentary
Fossiliferous Concretion
Septarian Concretion containing Brachiopods/Crinoids
fossil
Sedimentary Sandstone
Arenite (Sedimentary Rock)
sedimentary
Banded Siltstone / Mudstone Pebble
Siltstone / Argillite
sedimentary