sedimentary

Green Jasper with Quartz veins

Jasper (Silicon Dioxide, SiO2)

Mohs hardness 6.5-7. Color: Forest green with rusty iron staining and white/translucent quartz veins. Luster: Vitreous to waxy when wet/polished, dull when dry. Crystal structure: Microcrystalline (Trigonal). Breakage: Conchoidal fracture.

Luster: Vitreous to waxy when wet/polished, dull when dry

Identified April 8, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed from the deposition of silica-rich fluids (often in hydrothermal environments or via volcanic ash infiltration) into cracks or voids in rocks. The green color is often caused by silicate minerals like chlorite. These specimens are frequently found as water-worn river cobbles or beach stones.

Uses & applications

Used in the lapidary arts for cabochons, beads, and stone tumbling. Also used for ornamental carvings and as decorative garden stones.

Geological facts

Jasper is a dense, opaque variety of chalcedony. The name comes from the Greek word 'iaspis', meaning 'spotted stone'. It was highly prized in the ancient world for its supposed protective qualities and ability to treat stomach ailments.

Field identification & locations

Identify in the field by its hardness (it will scratch glass), smooth waxy texture when wet, and lack of visible grains. Often found in riverbeds or coastal areas where harder minerals accumulate after softer surrounding rock has eroded.

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