Lepidomelane

Lep`i*dom"e*lane (lĕp`ĭ*dŏm"ē*lān), n. [Gr. lepi`s -i`dos, a scale + me`las, me`laina, black.] (Min.) An iron-potash mica, of a raven-black color, usually found in granitic rocks in small six-sided tables, or as an aggregation of minute opaque scales. See Mica.