sedimentary
Yellow Jasper
Silicon Dioxide (SiO2) with iron impurities
Hardness: 6.5-7 (Mohs scale), Color: Mustard yellow to brownish-yellow, Luster: Waxy to dull, Structure: Microcrystalline quartz/Cryptocrystalline, Cleavage: None (Conchoidal fracture)
- Hardness
- 6
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Physical properties
Hardness: 6.5-7 (Mohs scale), Color: Mustard yellow to brownish-yellow, Luster: Waxy to dull, Structure: Microcrystalline quartz/Cryptocrystalline, Cleavage: None (Conchoidal fracture)
Formation & geological history
Formed from silica-rich groundwater percolating through sedimentary or volcanic rocks, often depositing in cracks or cavities. Its yellow hue comes from iron oxyhydroxides like goethite.
Uses & applications
Commonly used as a gemstone for jewelry (beads, cabochons), decorative carvings, and in alternative healing practices (metaphysical uses).
Geological facts
Jasper is an opaque variety of chalcedony. It has been used since ancient times for cylinders and seals, and 'Yellow Jasper' was historically known as a protective stone for travelers.
Field identification & locations
Identify by its hardness (cannot be scratched by a steel knife), opaque nature (unlike agate), and smooth, waxy feel when polished. Commonly found in riverbeds and arid regions globally, including South Africa, Brazil, and India.
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