sedimentary
Red Jasper with Quartz veins
Jasper (Silicon Dioxide, SiO2) with macrocrystalline Quartz veins
Hardness: 6.5–7 on Mohs scale. Color: Deep reddish-brown (from iron inclusions) with white to greyish veins. Luster: Dull/Waxy (surface) to Vitreous (veins). Structure: Microcrystalline with visible secondary fracture filling. Cleavage: None (conchoidal fracture). Specific Gravity: 2.58–2.91.
- Hardness
- 6
- Luster
- Dull/Waxy (surface) to Vitreous (veins)
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Physical properties
Hardness: 6.5–7 on Mohs scale. Color: Deep reddish-brown (from iron inclusions) with white to greyish veins. Luster: Dull/Waxy (surface) to Vitreous (veins). Structure: Microcrystalline with visible secondary fracture filling. Cleavage: None (conchoidal fracture). Specific Gravity: 2.58–2.91.
Formation & geological history
Formed through the deposition of silica from hydrothermal solutions or volcanic ash in sedimentary environments. The white veins are secondary quartz deposits that filled cracks in the rock as it underwent tectonic stress. Often Proterozoic to Phanerozoic in age.
Uses & applications
Used primarily for lapidary work (cabochons, beads), decorative garden stones, and as metaphysical 'healing' stones. In larger quantities, it can be used for aggregate or construction fill.
Geological facts
Red jasper has been used since antiquity by the Egyptians and Babylonians for amulets. The 'veins' in this specimen indicate that the host rock was once subject to high pressure, causing it to crack and allowing silica-rich water to flow through and crystallize.
Field identification & locations
Identify in the field by its hardness (cannot be scratched by a steel knife), smooth water-worn texture, and distinct color contrast. Commonly found in riverbeds, glacial tills, and rocky shorelines globally, notably in the Great Lakes region (USA/Canada) and South Africa.
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