Emily Dickinson Lexicon

DI-OP'SIDE, n. [Gr. διοψις.]

A rare mineral, regarded by Haüy as a variety of augite, and called by Jameson a subspecies of oblique-edged augite, occurring in prismatic crystals, of a vitreous luster, and of a pale green, or a greenish or yellowish white. The variety with four-sided prisms has been called Mussite, from Mussa in Piedmont. It resembles the Sahlite. – Cleaveland.