Not all fine gemstones are good to own. Here are seven doomed to bring their owners nothing but ill health, bad luck, misery and death.
A ring of silver enchanted such that if any in the wearer's presence intend to harm them it would grow warm. Unfortunately it's properties are wasted if in place of politics where it is consistently warm.
The multiple-worlds theory of cosmology allows room for every religion's Heaven and Hell and other planes to coexist, with the similar planes of all the sapient beings of all the worlds in all the galaxies...How often do the wires get crossed, as it were, leaving your paladin in a Hell for hedonistic lizards, for example.