sedimentary

Jasper

Silicon Dioxide (Microcrystalline Quartz, $SiO_2$)

Hardness: 6.5 to 7 on the Mohs scale. Color: Typically yellow, brown, red, or green, often multicolored or banded. Luster: Vitreous to dull. Crystal structure: Trigonal (microcrystalline/cryptocrystalline aggregate). Cleavage: None (exhibits conchoidal fracture). Specific gravity: 2.58 to 2.91.

Hardness: 6
Luster: Vitreous to dull

Identified July 31, 2026More sedimentary →

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Physical properties

Formation & geological history

Formed through the silification of sedimentary or volcanic deposits where silica-rich fluids replace organic or mineral structures over millions of years. Can be found in various geological settings worldwide dating from the Precambrian to recent epochs.

Uses & applications

Used primarily in lapidary arts, ornamental carvings, decorative objects, and occasionally as a gemstone in jewelry.

Geological facts

Jasper has been used by ancient civilizations for thousands of years to create tools, seals, and ornamental items. Its name means 'spotted or speckled stone.'

Field identification & locations

Identify in the field by its opacity, smooth water-worn texture when found in streams, conchoidal fracture, and inability to be scratched by a steel knife. Common worldwide in riverbeds and ancient marine deposits.

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