sedimentary
Red Jasper
Silicon Dioxide (SiO2) with Hematite impurities
Hardness: 6.5-7 (Mohs scale), Color: Rusty red to brownish-red, Luster: Dull or waxy when unpolished, Crystal Structure: Microcrystalline (trigonal), Cleavage: None/Conchoidal fracture, Specific Gravity: 2.58-2.91
- Hardness
- 6
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Physical properties
Hardness: 6.5-7 (Mohs scale), Color: Rusty red to brownish-red, Luster: Dull or waxy when unpolished, Crystal Structure: Microcrystalline (trigonal), Cleavage: None/Conchoidal fracture, Specific Gravity: 2.58-2.91
Formation & geological history
Formed via the accumulation of microcrystalline quartz from volcanic ash or silica-rich seafloor sediments, often during the Proterozoic or Paleozoic eras. The red color comes from iron inclusions (Hematite) during the silicification process.
Uses & applications
Used extensively in jewelry (cabochons, beads), decorative lapidary arts, spiritual/collecting practices, and historically for stone tools due to its durability.
Geological facts
Native Americans once called it the blood of Mother Earth. It has been used since antiquity in seals, amulets, and ring settings, notably mentioned in the Bible as one of the stones in the High Priest's Breastplate.
Field identification & locations
Identify by its deep red color, extreme hardness (it will scratch glass), and its lack of transparency. Common in river beds and desert environments, particularly in the western US, Brazil, and India.
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