Wiktionary
alluaudite
n. (context mineral English) A metasomatic mineral that is an alkaline manganese iron phosphate.
Wikipedia
Alluaudite
Alluaudite is a relatively common alkaline manganese iron phosphate mineral with formula (Na,Ca)Mn(Fe,Mn,Fe,Mg)(PO). It occurs as metasomatic replacement in granitic pegmatites and within phosphatic nodules in shales.
It was first described in 1848 for an occurrence in Skellefteå, Västerbotten, Sweden. It was named by Alexis Damour after François Alluaud (II) (1778–1866).