sedimentary
Jasper (Banded Jasper)
Silicon Dioxide (SiO2) with impurities
Hardness: 6.5-7 (Mohs); Color: Red, orange, yellow, and tan banding; Luster: Vitreous to waxy; Crystal structure: Microcrystalline/Cryptocrystalline; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.58-2.91
- Hardness
- 6
- Color
- Red, orange, yellow, and tan banding
- Luster
- Vitreous 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 (Mohs); Color: Red, orange, yellow, and tan banding; Luster: Vitreous to waxy; Crystal structure: Microcrystalline/Cryptocrystalline; Cleavage: None/Conchoidal fracture; Specific Gravity: 2.58-2.91
Formation & geological history
Formed from the deposition of silica-rich fluids in cavities or through the accumulation of silica-rich sediments. The banding occurs due to rhythmic precipitation of iron oxides and hydroxides during the stone's formation. These are often found as cobbles in riverbeds after eroding from volcanic or sedimentary host rocks.
Uses & applications
Used primarily as a gemstone for jewelry, lapidary arts (cabochons), and decorative ornamental objects. Historically used for making tools due to its hardness and sharp fracture edges.
Geological facts
Jasper is an opaque variety of chalcedony. The name 'jasper' means 'spotted or speckled stone,' derived via Old French and Latin from the Greek 'iaspis'. It has been a popular gemstone since antiquity, mentioned in numerous historical texts including the Bible.
Field identification & locations
Identify in the field by its opacity (unlike translucent agate), extreme hardness (it will scratch glass), and its characteristic smooth, rounded surface when found in water. It often displays distinct color bands or stripes from iron rich impurities.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite
sedimentary