[Moonman62]

Man made sapphires used for jewelry are sometimes given a coating of diamond to make them more durable and give them a better appearance. Sapphire is better than what they use now for displays, but it will still scratch.

[TexasGator]

“Man made sapphires used for jewelry are sometimes given a coating of diamond to make them more durable and give them a better appearance.”

Didn’t know that. Do you have more info on this?

[Swordmaker]

Man made sapphires used for jewelry are sometimes given a coating of diamond to make them more durable and give them a better appearance. Sapphire is better than what they use now for displays, but it will still scratch.

I think you have that upside down and backwards. Certain simulated diamonds are coated with sapphire to strengthen the surface to both prevent scratches and to improve surface reflectivity. DiamondNexus simulant stones have a Mohs hardness of 8.4, and a dispersion and refraction almost exactly the same as a diamond. That softness means there are a lot of materials that could potentially scratch the stone. To harden the surface and prevent scratches, it's coated with clear synthetic sapphire.