missourite

from Wiktionary, Creative Commons Attribution/Share-Alike License

• n. A leucite-augite rock, resembling ijolite but with leucite in place of nepheline.

from The Century Dictionary and Cyclopedia

• n. In petrography, a phaneric igneous rock composed of leucite, augite, and olivin, with smaller amounts of biotite, iron oxids, and apatite, occurring in the Highwood mountains, Montana.