brochantite

[broh-shahn-tahyt]

noun

a mineral, hydrous copper sulfate, Cu4(OH)6SO4, occurring in green fibrous masses and similar in physical properties to antlerite: formerly a major ore of copper.

Origin of brochantite

1860–65; named after A. Brochant de Villiers (1773–1840), French mineralogist; see -ite¹

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

Brochantite is a subsulphate of copper observed in small crystals at Ekaterinenbourg in Siberia.
A Dictionary of Arts, Manufactures and Mines
Andrew Ure