February - Amethyst. Adorn yourself with Lafonn's birthstone jewelry. The ring is set with a genuine round amethyst surrounded by Lafonn's signature Lassaire simulated diamonds in sterling silver bonded with platinum. Stone Count: 21 APPX CTW: 1.05 . AMETHYST APPX 0.85 CTS. LASSAIRE SIMULATED DIAMONDS: 0.20 CTS.