Rocks like quartz, well, quartz of optical quality weren´t cheap.

具有像石英这样的光学品质的石头并不便宜。

To this class of substance belong mica, porcelain, quartz, glass, wood, etc.

属于这类物质的有云母、瓷器、石英、玻璃、木材等等。

Nearly all computers contain a quartz-crystal clock to regulate their operation.

几乎所有的计算机都有一个石英晶体时钟来调节它们的运行。

The intense heat of the impact would produce heat-shocked quartz in many types of rock.

撞击所释放的强烈高温会在许多类型的岩石中形成一种热冲击石英。

For example, we have Quartz crystal clocks and watches accurate to within one minute a year.

例如，我们使用的每年误差不超过1分钟的石英水晶钟表和手表。