Mimetite
Image: <a href="//commons.wikimedia.org/wiki/User:Iifar" title="User:Iifar">Ivar Leidus</a> (CC BY-SA 4.0)
Mineral NameMimetite
Chemical FormulaPb5(AsO4)3Cl
Mohs Hardness3.5
Crystal Systemhexagonal
Lusterresinous
Streak Colorwhite to yellowish-white
Cleavageimperfect on {1010}
Fractureconchoidal to uneven
Specific Gravity7.24
Colorsgolden yellow, yellow, orange
Transparencytranslucent
Type LocalityCongreso-León mines, San Pedro Corralitos, Chihuahua, Mexico
Mineral GroupArsenates
Usescollector
Associated Mineralsgalena, cerussite, anglesite, quartz, iron oxides
Rarityuncommon
Description
This specimen displays golden yellow botryoidal masses of mimetite on a matrix, forming rounded, grape-like aggregates. The surface texture appears finely granular or crystalline, contributing to its resinous luster.
Geological Context
Mimetite is a secondary mineral typically found in the oxidized zones of lead ore deposits, where arsenic-bearing solutions react with primary lead minerals. It often forms in hydrothermal veins.
