I like where you're head is! I've been doing coin and artifact x-rays for years. Its the perk of working with a digital x-ray machine. The challenge is that both sides of the coin are superimposed onto one another in the resulting image making identification tough and small details hard to see. Imagine a modern quarter- the upside down eagle is on Washingtons head and the thicker parts of the coin combine, making it tough to distinguish any relevant details. I have a lump of 28 shipwreck coins held together with a matrix of nails and the pictures are awesome but it didn't shed any light on the type of coins.
Steve of PA posted a great article (as he always does) of how in the old days an expert heated an unidentifiable coin (in the story it was a shipwreck coin) in the fireplace until it was glowing hot and the details such as bust, date etc would present themselves and reveal the provenance of the coin. The energy given off in that scenario is first infrared, then becomes far red until it reaches red as perceived by our eyes as glowing. I would postulate that with the correct energy input, and a decent infrared camera ( most home security systems with " low light" capabilities) we could dial this in and come up with a decent technique to ID latent details without needing to subject the coin to undue thermal stress like the coin in the article. Basically i love physics, I am bored and you gave me a great idea to play with. I'll let you know if i can find any literature on the subject and I'll run a few tests n let you know what i get.
