Diamonds are not ordinary stones; some are jewels to wear history with. One of the loveliest and most highly treasured vintage diamonds is the Old Cut, a handcrafted 18th- to 19th-century diamond. They were cut in Old Cuts, unlike modern machine-cut diamonds, which are designed to maximize sparkle, and their glow in candlelight was warm and romantic, giving them a bold, antique demeanor. Five...