sedimentary
Jasper (Red and Yellow Jasper)
SiO2 (Silicon Dioxide) with Iron Oxide inclusions
Hardness: 6.5-7.0 (Mohs scale), Color: Variegated red, yellow, and brown, Luster: Vitreous to dull, Crystal structure: Microcrystalline/Cryptocrystalline, Cleavage: None (Conchoidal fracture), Specific gravity: 2.6-2.9
- Hardness
- 6
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: Variegated red, yellow, and brown, Luster: Vitreous to dull, Crystal structure: Microcrystalline/Cryptocrystalline, Cleavage: None (Conchoidal fracture), Specific gravity: 2.6-2.9
Formation & geological history
Formed via the deposition of silica from water-rich environments or hydrothermal solutions, often in volcanic or sedimentary beds. The coloration is primarily due to iron oxide impurities (Hematite for red, Goethite for yellow).
Uses & applications
Used extensively in jewelry as cabochons or beads, ornamental decor, lapidary arts, and stone tool making in ancient times.
Geological facts
Jasper is a variety of chalcedony. It is completely opaque, unlike its cousin Agate which is translucent. It has been used for seals and amulets since the Mycenaean civilization.
Field identification & locations
Identify by its hardness (cannot be scratched by a steel knife), opaque nature, and smooth, waxy feel when wet. Commonly found in riverbeds, gravel pits, and desert washes.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite
sedimentary