Agate
Image: <a href="//commons.wikimedia.org/wiki/User:Sailko" title="User:Sailko">Sailko</a> (CC BY-SA 3.0)
Mineral NameAgate
Chemical FormulaSiO2
Mohs Hardness6.5
Crystal Systemtrigonal
Lustervitreous
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity2.6
Colorswhite, cream, pink, brown
Transparencytranslucent
Type LocalityBrazil, Uruguay
Mineral GroupSilicates
Usesjewelry, ornamental objects, industrial, collector
Associated Mineralsquartz, amethyst, calcite
Raritycommon
Description
These are backlit slices of agate, displaying intricate concentric banding in shades of white, cream, light pink, and various browns, with a more crystalline or radial pattern towards the center.
Geological Context
Agate forms in cavities within volcanic rocks, such as basalt, where silica-rich fluids deposit successive layers of microcrystalline quartz (chalcedony) over time, often creating geodes or filling the entire void.
