Yellow fibrous ardennite-(V) associated to red piemontite from the type locality in Italy: Rio dei Piani, Feilongo, Torino Province, Piedmont. Ex. Erich Laskowski collection. — Photo: David Hospital · CC BY-SA 4.0
Ardennite-(V)
Ardennite-(V) is an IMA-recognized mineral species in the silicate class, with the chemical formula Mn²⁺₄Al₄(AlMg)(VO₄)(SiO₄)₂(Si₃O₁₀)(OH)₆.
It crystallizes in the orthorhombic crystal system (space group Pnmm). It is a member of the Ardennite structural group.
Key properties: Mohs hardness 6–7; specific gravity 3.55; White streak; Vitreous luster.
IMA symbol Ard-V, IMA status: approved, named in 2005.
Found in a quartz veinlet in piemontite-bearing mica schist.
It is found associated with Quartz, piemontite, hematite, muscovite.
As the vanadium analog of aredennite, first described from Salmchäteau, Ardennes Mountains, Belgium.