Enormous turquoise nugget. Kingman Area, Cerbat Mountains, Mohave County, Arizona, USA. photo Heritage Auctions

This gigantic Turquoise nugget is one of the largest ever found. Weighing in at a huge 103 pounds, this surreal piece features a light blue glossy band cutting across the piece of otherwise greenish-blue Turquoise. The surface texture is extremely intricate with an abundance of crevices and crenelations. Discovered in 1979, the nugget is one of the three largest ever found in the United States. The fine color is all natural with no treatment, and it shows excellent hardness for Turquoise. In form and color, it is arguably better than a slightly larger piece currently on display in Sedona, Arizona. The other contender of the three, was carved into a sculpture and currently resides in an exhibit at the J. W. Cooper Gallery in the Time Warner Building in New York City. The custom stand is composed of wood and metal. The base appears to be of South-Western Mesquite or Ironwood which helps to enhance the thematic impact of the specimen. This exquisite piece is remarkable in size. The nugget measures 22" in. (56 cm) x 18 in. (46 cm) x 8 in. (20 cm). It mounts on a wooden stand that is 12 in. (30.5 cm) tall making the total height of the piece on the stand 34 in. (86 cm). Estimate: $200,000 - $250,000.

Heritage Auctions. 2012 May 20 Natural History Signature Auction- New York