Fire Opal
Image: <bdi><a href="https://www.wikidata.org/wiki/Q56247090" class="extiw" title="d:Q56247090"><span title="mineral collector and dealer">Robert M. Lavinsky</span></a></bdi> (CC BY-SA 3.0)
Mineral NameFire Opal
Chemical FormulaSiO₂·nH₂O
Mohs Hardness5.5
Crystal Systemamorphous
Lustervitreous
Streak Colorwhite
Cleavagenone
Fractureconchoidal
Specific Gravity2
Colorsorange, yellow, red, brown
Transparencytranslucent
Type LocalityRodriguez Dam, Tijuana, Municipio de Tijuana, Baja California, Mexico
Mineral GroupSilicates
Usesjewelry, collector
Associated Mineralschalcedony, obsidian, rhyolite
Rarityuncommon
Description
A translucent, amber-orange fire opal specimen exhibiting a waxy to vitreous luster, partially embedded in a reddish-brown host rock matrix.
Geological Context
Fire opal typically forms in volcanic rocks, such as rhyolite or basalt, where silica-rich waters deposit amorphous silica in cavities and fissures.
