| 释义 |
〔obsidian〕A usually black or banded, hard volcanic glass that displays shiny, curved surfaces when fractured and is formed by rapid cooling of lava.黑曜岩:火山玻璃,一般为黑色,带状,摔碎时色泽光亮,表面变曲,由火山熔岩迅速凝而成〔perlite〕A natural volcanic glass similar to obsidian but having distinctive concentric cracks and a relatively high water content. In a fluffy heat-expanded form perlite is used as a lightweight aggregate, in fire-resistant insulation, and in soil for potted plants.珍珠岩:一种天然火山玻璃岩,类似于黑曜岩,但它有清晰的同轴裂纹和相对高的含水量。轻的热膨胀形珍珠岩可用作轻型建材,也可用于绝热材料和盆栽植物的土壤中〔pitchstone〕Any of various volcanic glasses distinguished by their dull pitchlike luster.松脂石:某种火山玻璃,以其暗似沥青的光泽而著名 |