Just appalling. I wonder if anybody has made a study of the dates and denominations which are toned in this way. Given that they are for the most part artificially toned, it seems to me to make sense to only tone relatively common, but high grade coins, so that any problems with the process won't result in a significant financial loss. In this way profits can be maximised without too great a risk. If this is the case, then again it lends substance to the argument that rainbow toning is an artificial process. Otherwise both common and rare coins would show this feature. Thus if RT was natural, I'd expect there to be a 1934 crown with it out there, but somehow I'm betting there isn't. Similarly, has anybody seen a RT coin with significant wear? After all, if the toning occurs naturally and a worn coin was taken out of circulation say 100 years ago, it should by now show rainbow toning. I accept that in circulation, you wouldn't expect it, but once this is no longer the case, a coin should tone according to the environment it's in. That should lead to some RT coins in fine condition, yet, I dont think i've ever seen one - please correct me if I'm wrong. Even if I accept the argument that collectors only want high grade examples and that such collectors store their coins in particular conditions that lead to RT occurring, I'd still expect to see some lower grade examples, if only where gaps are filled, due to the rarity of the date. Of course, if RT is artificial, then the reason for this is obvious - there's little price mark up on a worn coin. Perfect logic Dave, and I think we all know the answer to how many RT 1934 crowns are out there!