absarokite

(ab-sa'-ro-kite)

A trachyandesite , composed of phenocrysts of olivine and clinopyroxene in a groundmass of labradorite with alkali feldspar rims, olivine, and some leucite. Absarokite grades into shoshonite with a decrease in the olivine content and with the presence of some dark-colored glass, and into banakite with a decrease in the olivine and augite. It was named by Iddings in 1895 from the Absaroka Range, Wyoming.