Black microcrystals of the very rare copper sulphide yarrowite from New Mexico (High Rolls District, Otero County, New Mexico, United States of America). Ex Vandenbroucke Museum collection from Waregem, Belgium. — Photo: David Hospital · CC BY-SA 4.0
Yarrowite
Yarrowite is an IMA-recognized mineral species in the sulfide class, with the chemical formula Cu₉S₈.
It crystallizes in the hexagonal crystal system.
Key properties: specific gravity 4.89; Metallic luster.
IMA symbol Yar, IMA status: approved, named in 1978.
Occurs as weathering-produced lamellar replacements of other copper sulfides in stratabound red-bed copper deposits (Yarrow and Spionkop Creeks, Canada).
It is found associated with Anilite, djurleite, spionkopite, tennantite (Yarrow and Spionkop Creeks, Canada).
The name is taken from the type locality at Yarrow Creek, Canada.