Carbonado in the pores that are common in carbonados, they may have been introduced after carbonado formation. Inclusions of other minerals, rare or nearly absent in the Earth's crust, are found at least partly incorporated in diamond, not just in pores: among such other minerals are those with compositions of Si, SiC, and Fe‑Ni. No distinctive high-pressure minerals, including the hexagonal carbon polymorph, lonsdaleite, have been found as inclusions in carbonados, although such inclusions might be expected if carbonados formed by meteorite impact. Isotope studies have yielded further clues to carbonado origin. The carbon isotope value is very low (little carbon‑13
Carbonado, Washington and with it came the end of the need for the lower grade coal being mined at Carbonado and the timber being harvested for use in the settlements further up the valley. Since the decline of the mining era, Carbonado has experienced extreme shrinking and small booms ultimately ending with a steady population. All of the current residents work elsewhere and what was once an economic center for the valley is now a residential community. The railroad also pulled out and destroyed its towns quite recently. The Rails to Trails project has most of the actual rail line land in