Here is a fancy $1.28 million watch from Greubel Forsey. Mere plastic isn’t protecting the interior of the watch. No, it’s transparent sapphire. Transparent sapphire. ::transparent sapphire::. Transparent sapphire. Sorry, I’m just trying to understand what transparent sapphire is, which I guess is just this sapphire (very blue) made see-through. Maybe like Apple's sapphire glass? Got it.