Eldorado is a 31,000 ct. topaz that's part of the Special Exhibition Gems collection of the Programa Royal Collections Group, a European economic interest group founded in 1997 to create large-scale collections of gemology, art, and science. Those collections are meant to serve as the basis for cultural tourism projects. Eldorado was discovered in 1984 in Minas Gerais, Brazil. Uncut, it weighed an astonishing 37 kilos. According to its Web site, PRC has several cut gemstones that are considered the largest of their kind, including the Lua de Marabá, the second-largest cut topaz in the world, weighing 25,250 cts. The Special Exhibition Gems collection contains 20 gemstones, totaling more than 117,000 cts. It includes the Sol del Sur, an 8,200 ct. cut citrine; Minas Gerais, a 2,205 ct. aquamarine; and Corazón Verde, a 456 ct. emerald. For more information, visit www.prc-aeie.com.