Sapphire glass grade ?

[tom2517]

Originally Posted by SearChart

This is the first time I hear about this, I thought they were all pretty much the same. The finishing quality will of course differ, as will the quality of AR coating.

Yep, that's what I understand as well, only the cut and finishing quality differ. When I went to Urwerk HW in Geneva, they said their complicate shaped sapphire glass was cut and finished in Japan, not that the glass is any special, but the Japanese company was the best at cutting and finishing unusual shaped sapphire glass.