虽然蓝宝石表镜硬度高，理论上只有金刚石才能划伤它，但不代表就万事大吉，还要防止撞击和掉落震碎表镜。

Although high hardness sapphire table mirror, only the diamond can cut it in theory, but does not mean that everything is all right, but also to prevent collision and fall break table mirror.

youdao

虽然蓝宝石表镜硬度高，理论上只有金刚石才能划伤它，但不代表就万事大吉，还要防止撞击和掉落震碎表镜。

Although high hardness sapphire table mirror, only the diamond can cut it in theory, but does not mean that everything is all right, but also to prevent collision and fall break table mirror.

youdao