What is "valleriite"

n. (context mineralogy English) A trigonal-hexagonal scalenohedral mineral containing aluminum, copper, hydrogen, iron, magnesium, oxygen, and sulfur.

Valleriite is an uncommon sulfide mineral (hydroxysulfide) of iron and copper with formula: 4(Fe,Cu)S·3(Mg,Al)(OH) or (Fe,Cu)(Mg,Al)S(OH,O). It is an opaque, soft, bronze-yellow to brown mineral which occurs as nodules or encrustations.