Sedimentary Rock

Red Jasper

Jasper (a cryptocrystalline variety of Quartz, SiO₂)

Hardness: 6.5-7 on the Mohs scale. Color: Commonly red due to iron impurities, but can also be brown, yellow, green, or black. Luster: Dull to waxy. Crystal Structure: Microcrystalline (individual crystals are too small to be seen without magnification). Cleavage: None, exhibits conchoidal fracture.…

Hardness: 6
Luster: Dull to waxy

Identified August 3, 2025More sedimentary rock →

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Physical properties

Formation & geological history

Formed from the precipitation of silica from water, often in volcanic or hydrothermal environments. Microscopic quartz crystals grow within a silica gel, trapping various mineral impurities, most commonly iron oxides (hematite) which give it its characteristic red color. It can form in a wide range of geological ages, from Precambrian to Cenozoic, depending on the specific deposit.

Uses & applications

Jasper is widely used as an ornamental stone, for carving, and in jewelry (cabochons, beads). Due to its hardness and durability, it can also be used for abrasive purposes, although less common than other materials.

Geological facts

Jasper has been used since ancient times for carving, tools, and decorative objects. It was a favorite gemstone in the ancient world and is mentioned in the Bible. Various patterns and colors of jasper are often given unique common names, such as 'picture jasper' (with landscape-like patterns) or 'ocean jasper.'

Field identification & locations

Red Jasper is commonly found worldwide, often in areas with volcanic activity or sedimentary environments where silica-rich fluids were present. Significant deposits are found in the USA (Oregon, California, Idaho), Russia, India, Egypt, and Australia. In the field, it can be identified by its solid red to reddish-brown color, opaque appearance, and resistance to scratching from a steel knife (due to its hardness). Its conchoidal fracture is also a distinguishing feature.

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