[adambard]

There's a very good reason to use sapphire: since it has a (slightly) lower hardness than diamond, you can cut it into sheets with a diamond saw.

Sapphire still has a very high hardness, much better than glass of any sort.

[46Bit]

If we fast forward 20 years, I wonder if we could be a graphene 'sawing' diamond?

[Xcelerate]

Graphene's just a one atom thick sheet of graphite ;)

(Source: I research graphene.)

[46Bit]

Given that much of Graphite's weakness is due to sliding sheets, I was under the impression a single sheet would be far stronger?