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 settled during an economic boom in the region. The boom was brought on by raw material demands in nearby growing towns such as Seattle and Tacoma. Starting with the town of Burnett and moving on through Wilkeson, Carbonado, Montezuma, Fairfax, and finally Manley Moore, these settlements sprawled up the valley to the very boundary of Mount Rainier National Park. Most of these towns were company towns, meaning that they specialized in the harvest of raw materials owned the plot of land that the town was situated on and that the resources were harvested from. Often—and such was the case of