Carbonado typical gem diamonds. Lead isotope analyses have been interpreted as documenting crystallization of carbonados about 3 billion years ago. The carbonados are found in younger sedimentary rocks. Mineral grains included within diamonds have been studied extensively for clues to diamond origin. Some typical diamonds contain inclusions of common mantle minerals such as pyrope and forsterite, but such mantle minerals have not been observed in carbonado. In contrast, some carbonados do contain inclusions of minerals characteristic of the Earth's crust: these inclusions do not necessarily establish formation of the diamonds in the crust, however, because while these obvious crystal inclusions occur
Carbonado, Washington Carbonado—the company also owned the houses and the energy resources as well. The energy resource in Carbonado was also the raw material that the citizens of the company town were harvesting, coal. During the time of the initial boom in the valley Carbonado grew to rival the size of Tacoma at the time. The railroad, which was integral to the transportation of people, of the raw materials harvested and the supplies need by the towns, stretched all the way up the valley too. Not only did it service the towns but also several homesteads farther up the valley. These homesteads