Inky, luminous, and subtly sophisticated. There’s a reason Tahitian “black pearls” are among the most sought-after additions to a jewelry box and a coveted memento of what may be the most exotic and romantic escape. Entire honeymoons are designed around visiting exotic lagoons, choosing an heirloom piece of jewelry and returning home with an iridescent miracle of nature in a velvet box. A Pearl of a GemUnlike mineral gems, pearls are organic, marine miracles, created individually inside oysters. If an irritant,...