holdenite
noun
hol·den·ite
ˈhōldəˌnīt
plural -s
: a mineral (Mn,Ca)4(Zn,Mg,Fe)2(AsO4)(OH)5O2 consisting of a basic manganese zinc arsenate with minor calcium, magnesium, and iron and occurring as red orthorhombic crystals at Franklin, New Jersey
Word History
Etymology
Albert F. Holden †1913 American mining engineer + English -ite