Quartz-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 NameQuartz-Agate
Chemical FormulaSiO2
Mohs Hardness6.5
Crystal Systemtrigonal
Lustervitreous
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity2.65
Colorsred, orange, white, cream
Transparencytranslucent
Type LocalityWorldwide
Mineral GroupSilicates
Usesjewelry, ornamental objects, collector's item
Associated Mineralschalcedony, calcite, zeolites
Raritycommon
Description
This specimen is a nodular agate, often called a 'potato stone,' featuring vibrant red and orange banded patterns within a creamy matrix, with a central cavity lined by sparkling white druzy quartz crystals.
Geological Context
Agate forms in cavities within volcanic or sedimentary rocks where silica-rich solutions deposit successive layers of chalcedony, often culminating in the growth of quartz crystals in the remaining void.
