Among the convertible jewels in the Le Secret collection by Van Cleef & Arpels, this Pegase necklace features a 45.10-carat emerald-cut sapphire, surrounded by diamonds, emeralds and sapphires set in 18-karat white gold. What’s the secret? The center diamond pendant opens to reveal a tiny Pegasus crafted of diamonds (the pendants is also detachable). Price upon request, 877.828.25333, vancleefarpels.com