shonkinite
noun
shon·kin·ite
ˈshäŋkəˌnīt
plural -s
: a dark granular igneous rock consisting of augite with subordinate orthoclase and smaller amounts of olivine, biotite, nephelite, sodalite, and plagioclase
Word History
Etymology
Shonkin (Highwood mountains, Montana), its locality + English -ite