Cyanotrichite
Image: Robert M. Lavinsky (CC BY-SA 3.0)
Mineral NameCyanotrichite
Chemical FormulaCu₄Al₂(SO₄)(OH)₁₂·2H₂O
Mohs Hardness2.5
Crystal Systemorthorhombic
Lustersilky
Streak Colorpale blue
Cleavageperfect on {100}
Fractureuneven
Specific Gravity2.85
Colorssky-blue, azure-blue, light blue
Transparencytranslucent
Type LocalityGrand View Mine, Arizona, USA
Mineral GroupSulfates
Usescollector
Associated Mineralsbrochantite, malachite, chalcoalumite, azurite, chrysocolla
Rarityuncommon
Description
This image displays vibrant sky-blue cyanotrichite forming delicate, acicular (needle-like) crystals that often radiate outwards, creating a fuzzy or velvety texture on the host rock.
Geological Context
Cyanotrichite is a secondary mineral found in the oxidized zones of copper deposits, typically forming in arid environments. It results from the alteration of primary copper sulfides in the presence of aluminum-rich host rocks.
