sedimentary
Jasper
Silicon dioxide (SiO2) with iron inclusions
Hardness: 6.5-7 on Mohs scale; Color: Reddish-brown; Luster: Vitreous to dull; Crystal structure: Microcrystalline/Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91
- Hardness
- 6
- Color
- Reddish-brown
- Luster
- Vitreous to dull
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: Reddish-brown; Luster: Vitreous to dull; Crystal structure: Microcrystalline/Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58-2.91
Formation & geological history
Formed from silica-rich sediment or volcanic ash deposits where silica precipitates from water. Its red-brown color is typically due to iron oxide (hematite) inclusions within the quartz matrix. It can range from Precambrian to modern in age.
Uses & applications
Used primarily as a gemstone for jewelry, in lapidary arts for cabochons, and as a decorative stone in carvings and mosaics.
Geological facts
Jasper has been used as a gemstone since antiquity; it was mentioned in various ancient cultures including the Minoans on Crete and ancient Egyptians who used red jasper for amulets.
Field identification & locations
Identify by its hardness (it will scratch glass), its opaque nature, and smooth conchoidal fractures. Commonly found in riverbeds or near ancient volcanic regions. It is a common find for beachcombers and rockhounds in various global locations.
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