Haüyne
Image: <a href="//commons.wikimedia.org/wiki/User:Strekeisen" title="User:Strekeisen">Strekeisen</a> (CC BY-SA 4.0)
Mineral NameHaüyne
Chemical Formula(Na,Ca)4-8[Al6Si6O24](SO4,S,Cl)1-2
Mohs Hardness5.5
Crystal Systemcubic
Lustervitreous
Streak Colorwhite
Cleavagedistinct on {110}
Fractureconchoidal
Specific Gravity2.45
Colorsblue, white, gray, green, yellow, red
Transparencytransparent
Type LocalityMelfi (Potenza, Italy)
Mineral GroupSilicates (Feldspathoid, Sodalite group)
Usescollector, gemstone
Associated Mineralsnepheline, leucite, pyroxene, amphibole, olivine, biotite
Rarityuncommon
Description
The image displays a euhedral to subhedral Haüyne phenocryst, appearing colorless to pale gray in plane polarized light, embedded within a fine-grained, dark igneous matrix. The crystal shows a distinct hexagonal cross-section and some internal fractures.
Geological Context
Haüyne is a characteristic mineral of silica-undersaturated alkaline igneous rocks, such as foidites, phonolites, and tephrites, crystallizing from magmas rich in alkalis and poor in silica.
