sedimentary

Jasper

Jasper (Silica/Quartz) - SiO2

Hardness: 6.5–7 (Mohs); Color: Reddish-brown to orange-brown due to iron inclusions; Luster: Vitreous to waxy; Structure: Microcrystalline; Cleavage: None (conchoidal fracture); Specific Gravity: 2.58–2.91.

Hardness: 6
Color: Reddish-brown to orange-brown due to iron inclusions
Luster: Vitreous to waxy

Identified April 6, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from silica-rich fluids filling fissures or voids in volcanic rock or sedimentary layers. Its color is derived from high concentrations of iron oxide (hematite) or goethite. It can form in various geological ages depending on local silica deposition.

Uses & applications

Used primarily as a gemstone for jewelry (cabochons), ornamental carvings, and historical use in making tools like seals and scrapers due to its hardness and smooth fracture.

Geological facts

Ancient civilizations called Jasper the 'mother of all stones.' It is an opaque variety of chalcedony that never lets light pass through, even at thin edges, distinguishing it from carnelian or agate.

Field identification & locations

Identify in the field by its waxy texture, smooth conchoidal (shell-like) fracture, and inability to be scratched by a steel knife. Common in riverbeds, desert pavements, and volcanic regions globally.