Agate
Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/14730981@N08">James Petts</a> from London, England (CC BY-SA 2.0)
Mineral NameAgate
Chemical FormulaSiO2
Mohs Hardness7
Crystal Systemtrigonal
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity2.65
Colorsreddish-brown, brown, grayish-white, cream
Transparencytranslucent
Type LocalityWorldwide
Mineral GroupSilicates
Usesjewelry, ornamental objects, collector's item, industrial applications
Associated Mineralsquartz, calcite, zeolites, opal
Raritycommon
Description
This is a rough, rounded specimen of agate, sometimes referred to as a 'potato stone,' exhibiting mottled reddish-brown, brown, and grayish-white hues on its uneven surface. A yellow sticker with the number '7' is affixed, indicating its Mohs hardness.
Geological Context
Agate typically forms within cavities of volcanic rocks, such as basalt, where silica-rich solutions deposit microscopic quartz crystals in concentric layers over time. It can also be found in certain sedimentary environments.
