pyrolusite

[pahy-ruh-loo-sahyt, pahy-rol-yuh-sahyt]

noun

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

Dictionary.com Unabridged Based on the Random House Unabridged Dictionary, © Random House, Inc. 2018

Examples from the Web for pyrolusite

Historical Examples of pyrolusite

Heated in an ignition tube yields water in abundance, otherwise it behaves like pyrolusite.
The Elements of Blowpipe Analysis
Frederick Hutton Getman
The substitution of potassium chlorate for pyrolusite is recommended when calcium chloride is present in the bittern.
Encyclopaedia Britannica, 11th Edition, Volume 4, Part 3
Various
How does pyrolusite effect the decolorizing of glass containing iron?
An Elementary Study of Chemistry
William McPherson
Its dioxide (pyrolusite) has been known from very early times, and was at first mistaken for a magnetic oxide of iron.
Encyclopaedia Britannica, 11th Edition, Volume 17, Slice 5
Various
As an ore of manganese it is much less abundant than pyrolusite or psilomelane.
Encyclopaedia Britannica, 11th Edition, Volume 17, Slice 5
Various

British Dictionary definitions for pyrolusite

pyrolusite

noun

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

Word Origin and History for pyrolusite

"manganese dioxide," 1828, the name given in Roman times, when it was used, in a heated state, to de-colorize glass, from Greek elements pyro- "by heat, by fire" (see pyro-) + lysis "a loosening" (see lose).