Cubic zirconia (CZ) looks a lot like a diamond, but is much less valuable. Suppose you find a diamond-looking gem in the cracks of a sidewalk. Devise a way of verifying whether it is a diamond or a cubic zirconia without damaging the gem. You have access to a laser pointer, which can be used in this effort. (Note: the index of refraction for a diamond is 2.419; for cubic zirconia it is 2.20.)