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.
Diamonds typically occur in a rock called Kimberlite and in related cousins (Lamproite). Although diamond crystals are found in Kimberlite and related rocks, the origin of diamond is more closely related to the fragments of peridotite and eclogite which are derived from the upper mantle, below cratonic (shield) areas.iamonds typically occur in a rock called Kimberlite and in related cousins (Lamproite). Although diamond crystals are found in Kimberlite and related rocks, the origin of diamond is more closely related to the fragments of peridotite and eclogite which are derived from the upper mantle, below cratonic (shield) areas.