Chalcedony
Image: Dave Dyet http://www.shutterstone.com http://www.dyet.com (Public domain)
Mineral NameChalcedony
Chemical FormulaSiO2
Mohs Hardness6.5
Crystal Systemtrigonal
Streak Colorwhite
Cleavagenone
Fractureconchoidal to uneven
Specific Gravity2.6
Colorsbrown, orange, red, white, grey, yellow
Transparencytranslucent to opaque
Type LocalityWorldwide (e.g., Brazil, Uruguay, India, USA)
Mineral GroupSilicates
Usesjewelry, ornamental objects, collector
Associated Mineralsquartz, calcite, zeolites
Raritycommon
Description
A group of polished chalcedony cabochons and tumbled stones, featuring varieties like banded agate, leopard skin jasper, and red jasper, displaying diverse patterns and earthy tones.
Geological Context
Chalcedony forms from silica-rich solutions at low temperatures, commonly filling voids in volcanic rocks or as a replacement mineral in sedimentary environments.
