sedimentary

Jasper (var. Ocean or Polychrome Jasper)

Silicon Dioxide (SiO2) with iron and mineral inclusions

Hardness: 6.5-7 (Mohs scale); Color: Pink, reddish-brown, and tan mottled patterns; Luster: Vitreous to waxy; Crystal Structure: Trigonal (microcrystalline); Cleavage: None (conchoidal fracture); Specific Gravity: 2.58-2.91

Hardness: 6
Color: Pink, reddish-brown, and tan mottled patterns
Luster: Vitreous to waxy

Identified March 23, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the infiltration of silica-rich fluids into volcanic ash or sedimentary beds, where mineral impurities create varied coloring. Often found in deposits dating back to the Triassic or Cretaceous periods.

Uses & applications

Used primarily in lapidary arts for gemstones, beads, and cabochons. It is also a popular specimen for crystal collecting and metaphysical uses.

Geological facts

Jasper is an opaque variety of chalcedony. The name 'Jasper' is derived from the Greek word 'iaspis', meaning 'spotted stone.' Large deposits in Madagascar produce some of the most vibrant polychrome or oceanic varieties like the one pictured.

Field identification & locations

Identify in the field by its opacity (will not let light through even on thin edges), its characteristic conchoidal fracture, and it being hard enough to scratch glass. Found globally in deserts or volcanic regions; particularly common in the western United States and Madagascar.

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