Malachite
Image: <a rel="nofollow" class="external text" href="https://www.flickr.com/people/51035581380@N01">Deidre Woollard</a> (CC BY 2.0)
Mineral NameMalachite
Chemical FormulaCu2(CO3)(OH)2
Mohs Hardness3.5
Crystal Systemmonoclinic
Lustersilky
Streak Colorlight green
Cleavageperfect on {001}, good on {100} (rarely observed)
Fractureconchoidal to uneven
Specific Gravity3.9
Colorsgreen, dark green, banded green
Transparencytranslucent to opaque
Type LocalityDemocratic Republic of Congo, Russia, Arizona (USA)
Mineral Groupcarbonates
Usesjewelry, ornamental stone, pigment, minor copper ore, collector
Associated Mineralsazurite, chrysocolla, cuprite, native copper, goethite, calcite
Raritycommon
Description
A vibrant green mineral, often forming botryoidal or banded masses, sometimes with a silky luster. It is a copper carbonate hydroxide.
Geological Context
Malachite forms in the oxidized zone of copper deposits, typically as a secondary mineral resulting from the alteration of primary copper minerals by carbonic acid-rich waters.
