QUOTE(Doogy @ Jan 28 2006, 03:24 PM)
As a newbie to this hobby, can you fill me in on how this rainbow effect happens to coins? Is it an anomly that only happens to silver/silver content coins? I think the look is really neat! thanks for sharing
Doug
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It is toning and is caused by various things in the environment. Typically sulphur for silver. A lot of coins are stored in paper holders of one kind or another and a lot of paper has sulphur in it. Humidity, temperature, etc can affect it to.
Beware because there are artificial means to tone coins that are often detectable and not worth a premium.
Other metals can tone too as is seen with that Buff or even with a Lincoln toning Brown. Gold doesn't really tone much if at all but it is typically mixed with copper and that can lead to some color.