sedimentary (chemically precipitated) or metamorphic
Jasper (with orbicular/unakitoid tendencies)
Silicon Dioxide (SiO2) with iron and epidote inclusions
Hardness: 6.5–7 on Mohs scale. Color: Muted purple, grey, and green. Luster: Dull to waxy when unpolished. Crystal Structure: Hexagonal (microcrystalline/cryptocrystalline). Specific Gravity: 2.58–2.91.
- Hardness
- 6
- Color
- Muted purple, grey, and green
- Luster
- Dull to waxy when unpolished
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Physical properties
Hardness: 6.5–7 on Mohs scale. Color: Muted purple, grey, and green. Luster: Dull to waxy when unpolished. Crystal Structure: Hexagonal (microcrystalline/cryptocrystalline). Specific Gravity: 2.58–2.91.
Formation & geological history
Formed from the deposition of silica-rich fluids in volcanic ash or sedimentary beds. The coloration suggests the presence of iron oxide (purple/red) and potentially chlorite or epidote (green). These specimens are often shaped into 'river rocks' by water erosion over millions of years.
Uses & applications
Primarily used for lapidary work (cabochons, beads), decorative garden stones, and as metaphysical 'worry stones' due to their smooth, tumbled texture.
Geological facts
Jasper has been used by humans for thousands of years; it was a favorite in the ancient world for seals and amulets. The specific 'orb' or circular pattern visible on the bottom-center of the stone is a classic feature of orbicular jasper variations.
Field identification & locations
Identify in the field by its smoothness, lack of cleavage, and inability to be scratched by a steel knife. Commonly found in riverbeds, beaches, and glacial till across the Pacific Northwest and the Great Lakes regions of North America.
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