Haüyne
Image: <a href="//commons.wikimedia.org/wiki/User:Archaeodontosaurus" title="User:Archaeodontosaurus">Didier Descouens</a> (CC BY 3.0)
Mineral NameHaüyne
Chemical Formula(Na,Ca)4-8[Al6Si6O24](SO4,S,Cl)1-2
Mohs Hardness5.5
Crystal Systemcubic
Lustervitreous
Streak Colorwhite
Cleavagedistinct dodecahedral
Fractureconchoidal
Specific Gravity2.45
Colorsblue
Transparencytransparent
Type LocalitySan Vito quarry, San Vito, Ercolano, Monte Somma, Somma-Vesuvius Complex, Naples Province, Campania, Italy
Mineral Grouptectosilicates
Usescollector, gemstone
Associated Mineralsaugite, feldspar
Rarityuncommon
Description
A vibrant blue, transparent haüyne crystal, approximately 2 mm in size, exhibiting well-formed cubic or dodecahedral faces, set within a matrix of dark green augite and other clear mineral grains.
Geological Context
Haüyne typically forms in silica-undersaturated alkaline igneous rocks, such as phonolites and trachytes, often found in volcanic complexes like the Somma-Vesuvius, where it crystallizes from magma.
