sedimentary
Jasper
Jasper (Cryptocrystalline variety of Quartz, SiO2)
Hardness: 6.5-7.0 (Mohs scale); Color: Yellow, ochre, brown, and reddish-brown; Luster: Dull to waxy; Crystal structure: Hexagonal (trigonal) microcrystals; Cleavage: None, exhibits conchoidal fracture.
- Hardness
- 6
- Color
- Yellow, ochre, brown, and reddish-brown
- Luster
- Dull to waxy
Identified More sedimentary →
Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5-7.0 (Mohs scale); Color: Yellow, ochre, brown, and reddish-brown; Luster: Dull to waxy; Crystal structure: Hexagonal (trigonal) microcrystals; Cleavage: None, exhibits conchoidal fracture.
Formation & geological history
Formed from silica-rich groundwater that precipitates in the pores of sedimentary rocks or volcanic ash. The colors are derived from iron oxide inclusions (limonite for yellow, hematite for red). Found in many geological age strata worldwide.
Uses & applications
Commonly used in jewelry as cabochons or beads, ornamental lapidary work, and as a popular specimen for gem and mineral collectors.
Geological facts
Jasper is derived from the Greek word 'iaspis', meaning 'spotted stone'. It is an opaque form of chalcedony. Historically, it was believed to provide protection and grounding to its bearer.
Field identification & locations
Identify in the field by its opacity (even on thin edges), its smooth conchoidal fracture, and the fact that it cannot be scratched by a steel knife. Commonly found in riverbeds or desert areas.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite
sedimentary