A rare example of "chalcoborn" from Butte!!! Chalcoborn was at first thought to be a pseudomorph of chalcocite after bornite - however it was found that
it is an unusual scenario where both species are present in a habit that never underwent any "pseudomorphization"!!!
A very unusual, and rare occurence that is poorly understood!!! These specimens are very scarce indeed!!!
This specimen is from the collection of noted Butte collector and scholar, Bob Jenkins and retains his original label!!! If I can find any more information on
this unusual occurence I will be sure to add it to the auction - below is a short excerpt from an article cowritten by Jenkins in the Mineralogical Record from Jan/Feb 2002:
"'Chalcoborn,' a textural term originated by Charles Meyer, is an interesting
intergrowth that has been found at the Leonard, Steward, and other mines, The
material consists of dense, blue-black to purple-black aggregates of crystals
having the outward form of bornite, but actually consisting of chalcocite containing
minute inclusions of bornite. This is regarded as a primary texture, not a pseudomorph
(L. Zeihen, oral communication, 2000)."
Good luck and be sure to check out my other exciting mineral auctions on ebay!!!
PLEASE NOTE: We will be attending the Tucson Mineral Show from Jan. 29th - Feb.14th.
As such, auction specimens will ship immediately upon our return, in the order that payments were received.
As a token of our appreciation for your patience, all domestic shipping will be free of charge, and all international
shipping will be discounted by $5.50.
Please be sure to check our "About Me" page
for upcoming updates about our "Tucson Blog" and exciting new specimens from the show!!!
Tucson 2009 Show Blog
