Quartz (in Geode)
Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/65449832@N00">R'lyeh Imaging</a> (CC BY 2.0)
Mineral NameQuartz (in Geode)
Chemical FormulaSiO2
Mohs Hardness7
Crystal Systemtrigonal
Lustervitreous
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity2.65
Colorsclear, white, pale blue
Transparencytransparent to translucent
Type LocalityKeokuk, Iowa, USA
Mineral GroupSilicates
Usescollector's item, decorative, jewelry
Associated Mineralschalcedony, calcite, goethite
Raritycommon
Description
A macro photograph revealing a dense aggregation of small, sharp, clear to pale blue quartz crystals, likely lining the interior of a geode, exhibiting a sparkling, vitreous luster.
Geological Context
Geodes typically form in volcanic or sedimentary rocks where dissolved silica precipitates from groundwater into existing cavities, first forming an outer layer of chalcedony, then growing inward as larger quartz crystals.
