http://www.ebay.com/itm/Austria-Fra...966?pt=LH_DefaultDomain_0&hash=item3aa8265a66 Just saw this on eBay. I've never heard of a mirror brockage on both sides of a coin, and I'm not even sure that it's physically possible. At least not so perfectly clear on both sides. Seller seems to be reputable, but I can't see how this one is a genuine error. Thoughts?
Sure, it's possible. The first planchet is struck, get's stuck on the stationary die, a second planchet gets struck (it's now a single-brokage), gets stuck on the moveable die, and a third planchet get struck between the two coins stuck onto both dies. (Somebody's being lazy about the grease.)
I thought about that, but then the first coin to get stuck would have weakened details from striking the second coin to get stuck, also the second coin that got stuck would have some design elements from the first coin. Both of this would show on the third coin, but no sign of either on this one. Edit: In that scenario the third coin would have the same design on both sides, incuse on one and in relief on the other.
I thought it through and see that you are correct. Is it a hub trial strike perhaps? That could account for the incuse on both sides, and the sharp features.
It's possible I guess, though I've never seen or heard of that. And a double sided hub trial seems... weird. This coin just doesn't make a whole lot of sense to me
Hub trial and true die trials are typically done in lead or white metal and are one sided. There would be no reason to mount two hubs in a press and strike a copper planchet. This is almost certainly a "vise job" Possibly a very old one but not a mint error.
I don't see how this could be mint-made. First coin struck gets stuck, leaving only an obverse of the coin and obverse die to strike the next. The reverse die is now covered and can't impart a design on anything until the die cap is removed.