dannemorite
noun
dan·ne·mo·rite
ˌdanəˈmōrˌīt
plural -s
: a mineral (Fe,Mn,Mg)7Si8O22(OH)2 consisting of a columnar or fibrous amphibole containing iron, magnesium, and manganese
Word History
Etymology
Swedish dannemorit, from Dannemora, Sweden, + Swedish -it -ite