sedimentary

Jasper (Green Jasper/Heliotropic Chert)

Silicon Dioxide (SiO₂)

Hardness: 6.5-7 on Mohs scale; Color: Opaque dark green with brownish-yellow inclusions; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.6-2.9

Hardness: 6
Color: Opaque dark green with brownish-yellow inclusions
Luster: Vitreous to waxy

Identified March 24, 2026More sedimentary →

Identify your own rocks.

Get a report just like this from any photo, free.

App Store Google Play

Physical properties

Formation & geological history

Formed through the deposition of silica from hydrothermal solutions or volcanic ash in sedimentary environments. Its appearance is a result of fine-grained quartz mixed with impurities such as iron oxides and chlorite over millions of years.

Uses & applications

Commonly used in lapidary work for cabochons, beads, and tumbled stones. Historically used for making tools due to its conchoidal fracture, and currently popular for 'healing stones' and ornamental carvings.

Geological facts

Jasper is an opaque variety of chalcedony. This specific specimen appears to be water-worn or tumbled, and the name 'Jasper' is derived from the Greek word 'iaspis', meaning 'spotted stone.'

Field identification & locations

Identify in the field by its opacity (unlike translucent agate) and smooth, waxy feel when wet. Found commonly in riverbeds, glacial deposits, and coastal areas in regions like India, Brazil, and the Western United States. Collectors should look for unique internal patterns or 'eyes'.

Other sedimentary specimens

See all

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