Hauyne

Hauyne, haüyne or hauynite is a tectosilicate mineral with sulfate and chloride with formula: (Na,Ca)_4-8Al₆Si₆(O,S)₂₄(SO₄,Cl)_1-2. It is a feldspathoid and a member of the sodalite group. Hauyne crystallizes in the isometric system forming translucent, vitreous typically twinned crystals with highly variable color (blue, white, grey, yellow, green, pink). It has a Mohs hardness of 5 to 6 and a specific gravity of 2.4 to 2.5.

Hauyne was first described in 1807 from samples at Vesuvius Mount Somma, Italy. It was named for the French crystallographer, Rene Just Hauy (1743-1822). It occurs in silica deficient igneous rocks in a wide variety of locations.

References

• Mindat with location list
• Webmineral