sedimentary
Jasper
Silicon Dioxide (Microcrystalline Quartz, SiO2)
Mohs hardness of 6.5-7; colors range from brown, red, yellow, to green due to various mineral impurities; waxy to dull luster; cryptocrystalline or microcrystalline crystal structure; conchoidal fracture with no true cleavage; specific gravity of 2.58-2.91.
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Physical properties
Mohs hardness of 6.5-7; colors range from brown, red, yellow, to green due to various mineral impurities; waxy to dull luster; cryptocrystalline or microcrystalline crystal structure; conchoidal fracture with no true cleavage; specific gravity of 2.58-2.91.
Formation & geological history
Formed through the deposition of silica-rich fluids or silty sediments in marine or terrestrial environments, typically accumulating in beds or nodules, followed by diagenesis and lithification over millions of years.
Uses & applications
Used for ornamental objects, cabochons, carved gemstones, lapidary art, and historically for making tools or arrowheads due to its conchoidal fracture.
Geological facts
Jasper has been used by ancient civilizations since the 4th millennium BC for seals, jewelry, and ritual items. Its name means 'spotted or speckled stone' from ancient Greek.
Field identification & locations
Found worldwide in riverbeds, mountainous regions, and sedimentary rock formations. Identified easily by its opaque nature, hardness, waxy luster, and smooth conchoidal fracture surfaces.
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