eucrite
noun
eu·crite ˈyü-ˌkrīt 
1
: a stony meteorite composed essentially of plagioclase and pigeonite
2
: a rock consisting of a very basic gabbro
eucritic
yü-ˈkri-tik
adjective 
Word History
Etymology
German Eukrit, from Greek eukritos easily discerned, from eu- + kritos separated, from krinein to separate — more at certain
First Known Use
1881, in the meaning defined at sense 1