Jasper
Jasper (Silicon Dioxide, SiO2)
Rock Type: sedimentary

Physical Properties
Hardness: 6.5-7 (Mohs scale); Color: Yellow-orange to brownish-red; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None; Specific Gravity: 2.58-2.91
Formation & Geological History
Formed from the deposition of silica from water into volcanic ash or fine sediment, often stained by iron oxides during the sedimentary process. Most specimens date back to the Mesozoic or Cenozoic eras.
Uses & Applications
Commonly used as a gemstone for cabochons, beads, and architectural ornamentation. Historically used for making flint tools and seals.
Geological Facts
Jasper is an opaque variety of chalcedony. The name comes from the Old French word 'jaspre', meaning 'spotted or speckled stone'. Yellow jasper is traditionally associated with protection and solar energy in folklore.
Field Identification & Locations
Identify by its hardness (will scratch glass), opaque nature, and smooth, waxy feel when tumbled. Often found in riverbeds, coastal beaches, and desert plains globally.
Identified on: 5/1/2026
Mode: Standard