anyone have any ideas why we get coins like the one in the middle?? it's not just one side so here's a quick scan
(http://i42.tinypic.com/5eeb9e.jpg)
(http://i41.tinypic.com/2ytviok.jpg)
Most probably because the coin has been in some form of water/contaniment.
The middle one looks like an old 50c from 1970s :(
Quote from: 'ausjack' pid='28228' dateline='1379160980'anyone have any ideas why we get coins like the one in the middle??
Its oxidation. Probably a reaction with atmospheric gasses rather than fluids. I've seen freshly-minted examples, and I've wondered if the planchets could have been affected. Not done any research though, so its all just guesswork.