Alcantarillaite. Sphere section showing lamellar crystals, on quartz. Alcantarilla mine, Belacázar, Córdoba, Spain. Type locality — Photo: Miguel Calvo · CC BY-SA 4.0
Alcantarillaite
A calcium arsenate with iron and tungsten, described from the Alcantarilla mine in Córdoba, Spain.
Intro adapted from Wikipedia (CC BY-SA).
Alcantarillaite is an IMA-recognized mineral species in the arsenate class, with the chemical formula [Fe³⁺₀.₅(H₂O)₄][CaAs³⁺₂(Fe³⁺₂.₅W⁶⁺₀.₅)(AsO₄)₂O₇].
It crystallizes in the orthorhombic crystal system (space group Imma). It is a member of the Walentaite structural group.
Key properties: specific gravity 3.06; Pale yellow streak; Vitreous luster; optically biaxial.
IMA symbol Alc, IMA status: approved, named in 2019.
Secondary in the oxidation zone of a wolframite deposit (ferberite, löllingite).
It is found associated with Scorodite, pharmacosiderite, ferberite, schneiderhöhnite.
The name is derived from the locality where the studied material was collected.