sedimentary
Red Jasper
Silicon Dioxide (SiO2) - Microcrystalline Quartz
Hardness: 6.5-7 on Mohs scale; Color: Reddish-brown due to iron inclusions; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None; Specific gravity: 2.58-2.91
- Hardness
- 6
- Color
- Reddish-brown due to iron inclusions
- Luster
- Vitreous to dull
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Physical properties
Hardness: 6.5-7 on Mohs scale; Color: Reddish-brown due to iron inclusions; Luster: Vitreous to dull; Crystal structure: Trigonal (microcrystalline); Cleavage: None; Specific gravity: 2.58-2.91
Formation & geological history
Formed through the deposition of silica from water in cavities or as a byproduct of metamorphic and sedimentary processes. The red color is caused by iron oxide (hematite) impurities during formation.
Uses & applications
Commonly used in lapidary work, jewelry (cabochons and beads), decorative ornaments, and as a popular specimen for crystal collecting.
Geological facts
Jasper has been used throughout history as a gemstone. In ancient times, it was frequently used for seals and talismans. It is an opaque variety of chalcedony.
Field identification & locations
Identify in the field by its opaque nature, smooth waxy texture when polished, and high hardness (it will scratch glass). Often found in riverbeds or near silica-rich volcanic environments.
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