sedimentary
Chocolate Jasper
Microcrystalline Quartz (SiO2) with impurities
Hardness of 6.5 to 7 on the Mohs scale, dark brown or chocolate color with lighter quartz or calcite veining, waxy to vitreous luster, cryptocrystalline crystal structure, conchoidal fracture, specific gravity around 2.58 to 2.91.
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Physical properties
Hardness of 6.5 to 7 on the Mohs scale, dark brown or chocolate color with lighter quartz or calcite veining, waxy to vitreous luster, cryptocrystalline crystal structure, conchoidal fracture, specific gravity around 2.58 to 2.91.
Formation & geological history
Formed in sedimentary environments through the silification of clay-rich sediments or volcanic ash, where silica-rich fluids permeate and replace the original material over millions of years.
Uses & applications
Used primarily in lapidary arts, cabochons for jewelry, decorative carvings, and as a collector's mineral specimen.
Geological facts
Jasper is an ancient gemstone, frequently mentioned in historical texts dating back to Greek, Hebrew, and Roman antiquity where it was used for signet rings and protective amulets.
Field identification & locations
Identified easily by its distinctive chocolate brown background contrasted with white or beige web-like veins; commonly found in regions with ancient volcanic activity or sedimentary basins worldwide.
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