Sedimentary
Jasper (Iron-stained Quartzite/Chert)
Silicon Dioxide (SiO2) with iron oxide inclusions
Hardness: 6.5-7 on Mohs scale; Color: Rusty orange, brown, and yellow-tan; Luster: Dull to waxy; Crystal Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.9.
- Hardness
- 6
- Color
- Rusty orange, brown, and yellow-tan
- 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 on Mohs scale; Color: Rusty orange, brown, and yellow-tan; Luster: Dull to waxy; Crystal Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.6-2.9.
Formation & geological history
Formed through the accumulation of silica-rich sediments in aqueous environments, often during the Proterozoic or Paleozoic eras. The rounded shape suggests fluvial transport (water erosion) over a long period.
Uses & applications
Used primarily as decorative lawn stone, in lapidary work for cabochons, and historically for making stone tools due to its hardness and sharp fracture edges.
Geological facts
Jasper is an opaque variety of chalcedony. The reddish-brown coloration in this specimen is caused by the oxidation of iron (rusting) within the mineral matrix.
Field identification & locations
Identify in the field by its hardness (cannot be scratched by a steel knife), smooth water-worn texture, and dense, opaque appearance. Commonly found in riverbeds and glacial tilling across North America.
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