hypersthene
noun
hy·per·sthene ˈhī-pərs-ˌthēn 
: an orthorhombic grayish or greenish black or dark brown pyroxene
hypersthenic
ˌhī-pərs-ˈthe-nik
adjective -ˈthē-
Word History
Etymology
French hypersthène, from Greek hyper- + sthenos strength
First Known Use
circa 1808, in the meaning defined above