Perlite, obsidian and pitchstone are volcanic glass having the same compositions commonly with rhyolite as well as andesite and basalt.

、黑耀和松脂等玻璃质熔以酸性为主，中基性者也常见。

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.

进而分析了脉冲电场作用基中石墨晶核数量增加,有效地缩短了光分解时碳原子扩散距离,从而加速了第二阶段石墨化过程中光变。