sedimentary
Jasper (Red/Brown Variety)
Jasper (Microcrystalline Quartz, SiO2)
Hardness: 6.5–7 on the Mohs scale. Color: Brown to reddish-brown due to iron oxide inclusions. Luster: Vitreous when polished, waxy to dull when raw. Crystal structure: Trigonal/Microcrystalline. Cleavage: None (conchoidal fracture). Specific Gravity: 2.58–2.91.
- Hardness
- 6
- Color
- Brown to reddish-brown due to iron oxide inclusions
- Luster
- Vitreous when polished, waxy to dull when raw
Identified More sedimentary →
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 to reddish-brown due to iron oxide inclusions. Luster: Vitreous when polished, waxy to dull when raw. Crystal structure: Trigonal/Microcrystalline. Cleavage: None (conchoidal fracture). Specific Gravity: 2.58–2.91.
Formation & geological history
Usually forms from the deposition of silica from water or volcanic ash. It is frequently found in sedimentary environments or as primary deposits in hydrothermal veins. Because silica is very stable, specimens can range from a few million years to billions of years old.
Uses & applications
Commonly used in jewelry as cabochons, for lapidary art, as decorative tumbling stones, and historically as ornaments or tools due to its hardness and durability.
Geological facts
Jasper is an opaque variety of chalcedony. In ancient times, it was considered a 'rain bringer' and a stone of protection. The name comes from the Greek 'iaspis', meaning 'spotted stone.' It is almost always opaque, unlike its close relative Agate, which is translucent.
Field identification & locations
Identify in the field by its opacity (even when held to light), its smooth conchoidal fracture, and the fact that it cannot be scratched by a steel knife. It is commonly found in gravel beds, riverbanks, and desert regions worldwide, particularly in the western United States, Brazil, and India.
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