Whether you prefer round extravagance or a more angular glamour, Tiffany has you covered. On the left is the famed jeweler's oval diamond micromelee split shank ring. The 14.79-carat creation retails at $1.465 million. On the right, you'll find Tiffany's 12.03-carat cushion diamond ring, which sells for $800,000. Both rings are set in platinum. (Carlton Davis)