cummingtonitePronunciation: /ˈkʌmɪŋtənʌɪt/Definition of cummingtonite noun [mass noun] a mineral occurring typically as brownish fibrous crystals in some metamorphic rocks. It is a magnesium-rich iron silicate of the amphibole group. Origin: early 19th century: named after Cummington, a town in Massachusetts, US, + -ite1cummingtonite in other Oxford dictionaries Definition of cummingtonite in the US English dictionary
