sedimentary
Red Jasper
Jasper (Silicon Dioxide, SiO2 with iron oxide impurities)
Hardness: 6.5–7 (Mohs); Color: deep brick red; Luster: dull to vitreous when wet/polished; Crystal structure: Microcrystalline/Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58–2.91
- Hardness
- 6
- Color
- deep brick red
- Luster
- dull to vitreous when wet/polished
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Physical properties
Hardness: 6.5–7 (Mohs); Color: deep brick red; Luster: dull to vitreous when wet/polished; Crystal structure: Microcrystalline/Cryptocrystalline; Cleavage: None (conchoidal fracture); Specific gravity: 2.58–2.91
Formation & geological history
Formed through the deposition of silica from volcanic ash or hydrothermal solutions into voids and sedimentary layers. The red color comes from high concentrations of hematite (iron) during formation.
Uses & applications
Primarily used for lapidary work, jewelry (cabochons, beads), decorative carvings, and as a popular collector's stone due to its ability to take a high polish.
Geological facts
Jasper has been used for thousands of years; in ancient times, it was considered a 'rain bringer.' It is a member of the chalcedony family, distinguished by its opacity and iron content.
Field identification & locations
Identify by its solid red color, inability to be scratched by a steel knife, and smooth texture when water-worn. Commonly found in riverbeds and areas with volcanic activity or ancient sedimentary basins.
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