Meline: A pearl is one of the most complex gems to ... which is usually one color. High-quality black opal can cost over $10,000 per carat, making it one of the world's most expensive gemstones.

"I got grooves and grooves up on the shelf," he boasted on Daddy Pop. And the public agreed: Diamonds and Pearls, released in October 1991, boasted six singles, including Gett Off, Cream and Money ...