Bournonite, pyrite Mina Mercedes, Huallanca, Dos de Mayo, ...
Description: Bournonite, pyrite Mina Mercedes, Huallanca, Dos de Mayo, Huánuco, Peru 78 mm × 44 mm × 20 mm Also published at "Fabre Minerals Reference Specimens - The Silvane Collection" http://www.fabreminerals.com/specimens/RSSLV-silvane-notable-specimens.php#AL66M6