Thermoplastics, in basic terms, are melt-processable plastics (materials that are processed with heat). When enough heat is added to bring the temperature of the plastic above its melt point, the plastic liquefies (softens enough to be processed).
In the U.S., diamonds have been found in Arkansas, Colorado, Wyoming, and Montana. In 2004, the discovery of a microscopic diamond in the U.S. led to the January 2008 bulk-sampling of kimberlite pipes in a remote part of Montana.
A Colorado woman found an 8.52-carat diamond at Arkansas' Crater of Diamonds State Park at Murfreesboro. The gem found by Bobbie Oskarson of Longmont is the fifth largest diamond found at the park since 1972. She named it Esperanza for her niece's name and the Spanish word for 'hope' and plans to keep the diamond.