Mine, Altaiskiy Kray, Western Siberian Region, Russia
1.7x 1.4 cm
single crystal of cuprite that has pseudomorphed to copper.
There is still a bit of cuprite visible in a couple spots, making
for an interesting reminder of what it once was.
area has been producing cuprite for about 3 years now, but in 2011
there were also finds of these very interesting pseudomorphs.
The prices on these things have been consistently high-- unlike the
cuprites which came out in massive quantities (and whose prices have
moderated somewhat as a result), these pseudomorphs were only found
towards the end of work in the cuprite-bearing zone (which is now
finished), and in relatively small quantities. In other words,
these wont get any cheaper, only more expensive.