高温炉中的石英砂被加热熔化后，会玻璃化成透明的物质。

The quartz sand in the high-temperature furnace will ___vitrify into a transparent substance when heated and melted.

高温下，这块石头表面开始玻璃化，变得光滑透明。

Under high heat, the surface of the rock started to ___vitrify, becoming smooth and transparent.