Agate
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Mineral NameAgate
Chemical FormulaSiO2
Mohs Hardness6.5
Crystal Systemtrigonal
Lusterwaxy
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity2.6
Colorswhite, gray, blue, red, pink, brown, black, green, yellow, purple
Transparencytranslucent
Type LocalityWorldwide (e.g., Brazil, Uruguay, Mexico, USA, India)
Mineral GroupSilicates
Usesjewelry, ornamental objects, carvings, industrial
Associated Mineralsquartz, calcite, zeolites
Raritycommon
Description
Agate is a microcrystalline variety of quartz, characterized by its fine grain and often vibrant, concentric banding or layered patterns. It typically forms in geodes or as nodules.
Geological Context
Agate forms primarily in the cavities of volcanic rocks, such as basalt, where silica-rich solutions deposit in successive layers. It can also be found in some metamorphic rocks and as secondary deposits in sedimentary environments.
