Spionkopite & Yarrowite (rare copper sulphides), Spionkop Ridge, Alberta, Canada

Maybe they are not the prettiest minerals but they sure are rare. Spionkopite (Cu39S28)* and Yarrowite (Cu9S8)* are only found in a handful of localities worldwide, but the type locality is Spionkop Ridge, south of Pincher Creek, Alberta, Canada. This locality is just north of Waterton Lakes National Park and is quite picturesque with abundant wildlife. I distinctly  remember a humming bird zoom by me when I was collecting this piece in the late 1980s! The locality is an uneconomic copper showing in Precambrian-aged metamorphosed sediments and has been completely reclaimed since my collecting trip; new material is not coming out. Both copper sulphides are indistinguishable without the aid of XRD or other laboratory analysis but can be identified as black and bluish "blebs" surrounded by light green malachite in quartzite. This piece is a classic example, with several "blebs", and is an excellent reference specimen of something you will likely do not have. Ex Keith Mychaluk collection (#S-27-13). Dimensions: 5.5 x 6.5 x 10.5 cm  SOLD

*Sorry but subscripts do not work on Shopfiy so I apologize for the improper chemical formula format