sedimentary

Jasper

Silicon dioxide (SiO2)

Hardness: 6.5-7 (Mohs); Color: Dark green with brown/black mottling; Luster: Vitreous to waxy; Structure: Microcrystalline quartz; Cleavage: None/Conchoidal fracture; Specific gravity: 2.58-2.91

Hardness: 6
Color: Dark green with brown/black mottling
Luster: Vitreous to waxy

Identified May 20, 2026More sedimentary →

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Physical properties

Hardness: 6.5-7 (Mohs); Color: Dark green with brown/black mottling; Luster: Vitreous to waxy; Structure: Microcrystalline quartz; Cleavage: None/Conchoidal fracture; Specific gravity: 2.58-2.91

Formation & geological history

Formed through the deposition of silica from mineral waters or volcanic ash during early Earth periods, often occurring as nodules or in cracks in volcanic rock. This specific specimen shows signs of water-tumbled erosion, likely from a river or beach.

Uses & applications

Commonly used in jewelry (lapidary), as polished decorative stones, and in metaphysical collecting. Historically used for making tools and weapons due to its hardness and sharp fracture edges.

Geological facts

Jasper is an opaque variety of chalcedony. The name 'Jasper' is derived from the Greek 'iaspis', meaning spotted stone. Green jasper was often used in ancient seals and talismans.

Field identification & locations

Identify in the field by its opacity (even on thin edges), its hardness (will scratch glass), and its smooth, rounded shape if found near water. Look for it in river beds and gravel deposits.