Pot Cover Sapphire crystal watch glass

Sapphire crystal watch glass is unarguable material for watch glass. Since it developed for watch industry, more and more brands choose Sapphire glass. now the common sense for watch, Mechanical watch, 98% watch in sapphire glass. even some micron brands Premium quartz watch are in sapphire glass too. now the watch glasses are synthetic sapphire, it contains crystallized aluminum oxide. but they are in same physical feature as nature sapphire. hardness Mohr 9, just next to the highest Mohr 10 by Diamonds. there is a word, Sapphire glass can be only scratched by diamond or other sapphires. this feature to make the sapphire crystal as first choice.  Sapphire glass have several type too. 1. flat, common one and cheaper version, and more easy to produce. 2. Domed, just like a dome. of course the price of domed glass depends on the height of dome, higher height, more expensive price. 3. Pot cover, that means the glass shape like a Pot. not just curving. that is more expensive gla…