Agate
Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/47445767@N05">James St. John</a> (CC BY 2.0)
Mineral NameAgate
Chemical FormulaSiO2
Mohs Hardness7
Crystal Systemtrigonal
Lustervitreous
Streak Colorwhite
CleavageNone
Fractureconchoidal
Specific Gravity2.65
Colorswhite, cream, yellow, brown, orange
Transparencytranslucent
Type LocalityWorldwide
Mineral GroupSilicates
Usesjewelry, ornamental objects, industrial, collector
Associated Mineralsquartz, calcite, zeolites
Raritycommon
Description
This image displays a polished slice of agate, revealing intricate concentric and parallel banding in shades of white, cream, yellow, and brown, with a distinct eye-like pattern in the center.
Geological Context
Agate forms in cavities of volcanic rocks or ancient lavas, where silica-rich groundwater deposits successive layers of microcrystalline quartz (chalcedony) over time, often filling geodes.
