sedimentary
Jasper
Silicon dioxide (SiO2) with iron oxide and clay inclusions
Hardness: 6.5–7 on Mohs scale; Color: typically earthy tones (brown, forest green, yellowish); Luster: dull to waxy; Structure: cryptocrystalline quartz; Cleavage: none, conchoidal fracture; Specific gravity: 2.58–2.91
- Hardness
- 6
- Color
- typically earthy tones (brown, forest green, yellowish)
- 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: typically earthy tones (brown, forest green, yellowish); Luster: dull to waxy; Structure: cryptocrystalline quartz; Cleavage: none, conchoidal fracture; Specific gravity: 2.58–2.91
Formation & geological history
Formed through the deposition of silica from water-saturated solutions, often near volcanic activity or in sedimentary basins where mineral-rich water infiltrates ash or clay beds. Can range from hundreds of millions to billions of years old.
Uses & applications
Commonly used in lapidary arts for cabochons, beads, and carvings; historically used for jewelry and ornametal objects; sometimes used in industrial grinding due to its hardness.
Geological facts
Ancient civilizations called Jasper the 'mother of all stones.' The name comes from the Greek 'iaspis,' meaning spotted stone. It is distinctive for its opacity compared to translucent agate.
Field identification & locations
Identify in the field by its smooth, waxy feel when wet and its ability to scratch glass. It will show a curved (conchoidal) fracture when broken. Found globally, especially in riverbeds or mountain ranges in the Western USA, 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