Jasper

Jasper (Silicon Dioxide, SiO2 with iron inclusions)

Rock Type: sedimentary

Jasper

Physical Properties

Hardness: 6.5–7 on Mohs scale; Color: Red, orange, pink, or multicolored with banding; Luster: Vitreous to waxy; Crystal structure: Trigonal/Microcrystalline; Cleavage: None/Conchoidal fracture; Specific gravity: 2.58–2.91

Formation & Geological History

Formed through the deposition of silica-rich solutions in sedimentary environments or hydrothermal veins. The red/orange banding is caused by iron oxide (often hematite) impurities incorporated during the mineralization process over millions of years.

Uses & Applications

Primarily used as a gemstone for lapidary work, jewelry (beads, cabochons), carvings, bookends, and as a collector's specimen. It is also used in decorative architectural finishes.

Geological Facts

Jasper is a variety of chalcedony. Historically, it was known as the 'supreme nurturer' and has been used since antiquity in seals and ornaments. Red Jasper is specifically mentioned in various ancient religious and mythological texts.

Field Identification & Locations

Identify in the field by its hardness (it will scratch glass), its opaque nature, and its smooth, waxy feel when water-worn. Common in riverbeds, desert washes, and coastal areas throughout regions like the Western USA, Brazil, and India.

Identified on: 4/14/2026

Mode: Standard