I ordered these earrings from Amazon (Feb 2012), and I am returning them.

Simply stated, there is absolutely no way these stones look like real diamonds - even to the uneducated eye, even from a distance.  I'm not sure how anyone could possibly think they look like diamonds, unless they'd never seen real diamonds.

Instead of diamonds, they look like bits of glass, because
  1) There is no real fire in the depths.
  2) They do not reflect many colors.
  3) They don't really sparkle, even under strong light.
Honestly, Swarovski crystlas have more brilliance.

I gather that CZs come in a range of quality, having to do with density.  The cut can make a huge difference; these look molded, not cut.  These CZs are definitely on the lower end of the quality spectrum.  Check out Ross-Simons for good-quality CZ jewelry.

BUT... They are very inexpensive, and that is enough reason to order them.  You won't care if you lose one!  Just don't take them seriously, and don't embarass yourself by passing them off as diamonds.  People can tell from across the room they are fakes - just for fun.