sedimentary
Jasper
Silicon dioxide (SiO2)
Hardness: 6.5-7 (Mohs); Color: Reddish-brown; Luster: Dull to waxy; Crystal Structure: Microcrystalline; Cleavage: None (conchoidal fracture).
- Hardness
- 6
- Color
- Reddish-brown
- Luster
- Dull to waxy
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Physical properties
Hardness: 6.5-7 (Mohs); Color: Reddish-brown; Luster: Dull to waxy; Crystal Structure: Microcrystalline; Cleavage: None (conchoidal fracture).
Formation & geological history
Formed from silica-rich precipitates in sedimentary environments or hydrothermal veins. The red/brown color is due to iron inclusions.
Uses & applications
Used primarily for lapidary work, jewelry, decorative ornaments, and as a semi-precious gemstone.
Geological facts
Jasper is an opaque variety of chalcedony. In ancient times, it was called the 'supreme nurturer' and was believed to provide courage and physical strength.
Field identification & locations
Identify by its hardness (it will scratch glass), its opaque nature, and its smooth, water-worn texture when found in riverbeds or beaches.
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