perlite

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

珍珠岩、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。

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.

进而脉冲电场作用基体中石墨晶量增加,有效地缩短珠光体解时碳原子扩散距离,从而加速第二阶段石墨化过程中珠光体转变。