- Periclasite
- Periclase Per"i*clase, Periclasite Per`i*cla"site, n. [Pref. peri- + Gr. ? to break.] (Min.) A grayish or dark green mineral, consisting essentially of magnesia (magnesium oxide), occurring in granular forms or in isometric crystals. [1913 Webster]
The Collaborative International Dictionary of English. 2000.