Exotic South Sea pearls from the Black-Lipped Oyster, or Pinctada margaritifera, are more commonly known as Tahitian pearls. These pearls are often referred to as black, but have a remarkable colour range that covers the spectrum - from light, creamy white and grey, to regal greens and deep black. Tahitian pearls are relative newcomers to the pearl world, popularized only as early as the mid-1900's. Unlike the more common pearl types, Tahitian pearls typically have a naturally dark body color. These pearls have become some of the most sought-after, expensive pearls in the world. Because of their vast color range, matching these pearls into a finished strand is an enormous task requiring thousands of loose pearls to create a single strand. Tahitian pearls are considered to be the second most valuable commercially farmed pearls in the world. Unlike black freshwater and black Akoya pearls, which have been irradiated or dyed, Tahitians come by their dark color naturally. Tahitian pearls are bead-nucleated, but unlike Akoya pearls the nacre is typically very thick. Beautiful Tahitian pearls are among the largest pearls in the world. The beauty of Tahitian pearls, however, is not limited to their size, but their incredible array of iridescent colors. These colours are expressed in Tahitian pearls in a magical way with colours shimmering over the surface of some of the best specimens. Tahitian pearls were once some of the rarest, most valuable cultured pearls in the world. They are still much more valuable than freshwater and Akoya pearls, but the farming enterprises are no longer relegated to small island groups. Today Tahitian pearls, albeit still very expensive, are now affordable to a much wider demographic.