http://www.ngccoin.com/news/viewarticle.aspx?IDArticle=1591& I think this is neat. NGC is now doing metallurgic testing of coins you send in if you desire it.
Personally I would very rarely use this service. I can see where it would be very helpful with ancient coins and some error coins. There are some pattern coins that come in very similar metals and this would be useful there. There are uses... but they are specialized. I just thought it was neat.
I just was thinking that I probably would not use it and was trying to think of the possiblity's of who would. It still is a neat idea and useful for some.
I too think it's a good idea. On the other hand, things could get pretty ridiculous: Send in a coin to NGC, get your star, get a metallurgical analysis, ship it off to CAC, have them sticker it, send that in to PCGS, who will encase the whole thing in a gigantic slab, and give their plus-sign seal of approval, ship it to the Vatican and snap a picture of the Pope blessing the coin....
Only on something with an unknown metal content that would effect the value. It would matter little with ancient coins, unless they were to be used in an academic study. In that case, I would prefer to use either the (lamentably destructive) neutron-activation analysis or a much cheaper service. The real use would be for modern wrong-planchet error coins and patterns.
