UltrafastFS_IR_Laser

I don't think any sane person wants to visit Saudi Arabia anyways.

I can answer this. In applications for protection and what not, sapphire is much cheaper than diamonds, something which even lab manufactured diamonds will not be able to touch. Diamonds and sapphires have quite a lot in common too, with sapphires being just slightly less hard. The main prohibitive thing is the cost. It takes a lot more for labs to make the diamond compared to the sapphire and the gain in durability/scratch resistance is minimal.

Even in our lab, diamond isn't really that great and we prefer sapphire for nearly all applications besides cutting. Sapphires also have a cleaner optical window than diamonds.