Obsidianite definition: a glassy gemstone made by melting volcanic ash and rock and then rapidly cooling it before it can crystallize. See examples of OBSIDIANITE used in a sentence.
Sodium and potassium silicates (plagioclases) undergo melting at high temperatures and form continuous solid solutions [2], which, upon slow cooling, decompose into compounds containing sodium and potassium. These compounds contain isomorphous impurities, such as the magnetite Fe 2 O 3 and the ...
Thus melting markedly strengthens KR, and radiative heat transport is probably the dominant component of the total conductivity K = KL + KR in silicic magmas. These relatively large values of K can be applied to models of the thermal evolution of magma bodies and to cooling of intrusives.C....