sedimentary
Jasper (Green Jasper/Chert)
Silicon Dioxide (SiO2)
Hardness: 6.5–7 on Mohs scale; Color: olive green with reddish-brown oxidation veins; Luster: waxy to vitreous; Crystal structure: Microcrystalline (Trigonal); Cleavage: none (conchoidal fracture); Specific gravity: 2.58–2.91
- Hardness
- 6
- Color
- olive green with reddish-brown oxidation veins
- Luster
- waxy to vitreous
Identified More sedimentary →
Explore Jasper (Green Jasper/Chert) in the encyclopedia →Identify your own rocks.
Get a report just like this from any photo, free.
Physical properties
Hardness: 6.5–7 on Mohs scale; Color: olive green with reddish-brown oxidation veins; Luster: waxy to vitreous; Crystal structure: Microcrystalline (Trigonal); Cleavage: none (conchoidal fracture); Specific gravity: 2.58–2.91
Formation & geological history
Formed through the deposition of silica from water-saturated solutions or via the accumulation of radiolarian tests in deep marine environments. This specimen shows signs of river or water smoothing, creating its rounded edges.
Uses & applications
Commonly used for lapidary work, cabochons, polished decorative stones, and historical utility as strike-a-lights or flint tools.
Geological facts
Green jasper was used in antiquity as a medicine for symptoms ranging from stomach issues to snakebites and was highly prized in the ancient world for seal stones.
Field identification & locations
Identify in the field by its hardness (cannot be scratched by a steel knife) and waxy, smooth surface. Often found in riverbeds, gravel pits, or ocean beaches.
More like this
Other sedimentary specimens
Sandstone or Siltstone
Arenite (if sandstone)
Sedimentary
Cone-in-cone structure (Limestone)
Cone-in-cone structure (Secondary Sedimentary Structure)
sedimentary
Sandstone Grain
Clastic Sedimentary Rock Grain (SiO2 dominated)
sedimentary
Chert Breccia
Brecciated Chert (Microcrystalline Silica)
sedimentary
Shale or Slaty Mudstone
Argillaceous sedimentary rock
sedimentary
Sandstone
Arenite (primarily SiO2)
sedimentary