It might well have a resonant freq, the issue would be other things surrounding it might well have a similar resonance, depends on the testing environment, if your tesing a sample in a jar then maybe you'd be able to rig something up.
To test for a mechanical resonance you need a way to excite the material, maybe an impulse or a random noise generator, and a way to measure the motion of the material under test and be able to display its spectral content or signature, if its in the audio range then that would be a lot easier.