1.Perlite, obsidian and pitchstone are volcanic glass having the same compositions commonly with rhyolite as well as andesite and basalt.
岩、黑耀岩和松脂岩等玻璃质熔岩以酸性为主,中基性者也常见。
2.The result indicated that transformation of perlite was accelerated and the quantities of ferrolites was increased under the function of impulse electric field at second stage graphitization.