Why the hell do I have to get an MRI?

That isn’t correct, I don’t think. Some (not all) diamonds fluoresce under UV light, and what good would that do if someone swallowed them?

Speaking from many years of experience, I’ve yet to see one diamond glow from x-rays. And, unless the stone was covered with quite a bit of crud, and it was large enough, it would probably de difficult to find on a, let’s say, full abdomen x-ray.

eta: That chuck of rock that Bob Ducca linked to would definitely show up. Just not the diamond part.

This is most likely it. I work in a hospital doing security and I signed a form that sounds like this one. If you are at risk being in/around the magnetic field they want to know about (and so do you!).

How can I paste this onto Facebook?

I find that kind of funny, as I’ve never had to sign a form about the magnetic field from an NMR.

…say what now?

Someone asked the OP who told him he needed an MRI. He said he wasn’t told that by anyone, and explained he was sent a form.