[ pahy-ruh-loo-sahyt, pahy-rol-yuh-sahyt ]
/ ˌpaɪ rəˈlu saɪt, paɪˈrɒl yəˌsaɪt /


a common mineral, manganese dioxide, MnO2, the principal ore of manganese, used in various manufactures, as a decolorizer of brown or green tints in glass, and as a depolarizer in dry-cell batteries.

Origin of pyrolusite

1820–30; pyro- + Greek loûs(is) washing + -ite1 Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2019

Examples from the Web for pyrolusite

British Dictionary definitions for pyrolusite


/ (ˌpaɪrəʊˈluːsaɪt) /


a blackish fibrous or soft powdery mineral consisting of manganese dioxide in tetragonal crystalline form. It occurs in association with other manganese ores and is an important source of manganese. Formula: MnO 2

Word Origin for pyrolusite

C19: from pyro- + Greek lousis a washing + -ite 1, from its use in purifying glass
Collins English Dictionary - Complete & Unabridged 2012 Digital Edition © William Collins Sons & Co. Ltd. 1979, 1986 © HarperCollins Publishers 1998, 2000, 2003, 2005, 2006, 2007, 2009, 2012