These sprays have been identified as being intermediate windmountainite/tuperssuatsiaite. They are associated with aegirine, analcime and some orange/red balls of a smectite group mineral. They were collected on 3/14/2016. — Photo: Jerry Cone · CC0
Windmountainite
Windmountainite is an IMA-recognized mineral species in the silicate class, with the chemical formula Fe³⁺₂Mg₂Si₈O₂₀(OH)₂·8H₂O.
It crystallizes in the monoclinic crystal system (space group C2/m). It is a member of the Palygorskite, Clay structural group.
Key properties: Mohs hardness 2; specific gravity 2.51; Orange-brown streak; Dull, silky in aggregates luster.
IMA symbol Wmt, IMA status: approved, named in 2019.
Found in vesicles within a phonolite dike in a zoned, alkaline laccolith. Formed from late- stage fluids that were alkaline, oxidized, and rich in Fe3+ and H2O.
It is found associated with Albite, aegirine, fluorapophyllite-(K), natrolite, neotocite, montmorillonite. Distribution From Wind Mountain, Otero Co., New Mexico, USA.
The name refers to Wind Mountain where the studied material was collected.