Originally Posted by
volsfan0911 I'm not sure why apple couldn't have used the sapphire crystal across the board rather than ionx on the lower end models.
It could be market volume. Sapphire crystals are not the easiest things to make. Making enough at the volume of aluminum smartwatches that Apple sells may mean that they couldn't make enough fast enough. More likely, though, Apple is trying to keep their cost of materials down to a specific amount, and using sapphire crystals on aluminum watches means either too high a price, too low a profit, or a reduction in material quality in other parts of the watch.
But, that's just a guess.