An investment note we’ve seen from analyst and GTAT investor Matt Margolis claims that all 5.5-inch models of the iPhone 6 will come with sapphire screens, while the 4.7-inch model will get either sapphire or Gorilla Glass depending on the specification.

It should be noted that Margolis is on record as being heavily-invested in GTAT’s sapphire plant. He reported a week ago that Apple planned to expand production at the plant, citing a letter to the U.S. Department of Commerce advising of the plans.

The WSJ had earlier reported that sapphire screens would be reserved for the more expensive “of the two new iPhones,” in line with a JP Morgan prediction.

The analyst also repeats earlier rumors that the 4.7-inch iPhone 6 will go on sale in September, while both 5.5-inch model and iWatch won’t be available for purchase until October. Both models are, however, expected to be announced on 9th September.

The most recent alleged parts leaks appear to confirm that the new iPhones will be sold in a choice of three colors similar or identical to those of the iPhone 5s.

The latest reports suggest that the iWatch (which is pretty much guaranteed to have a sapphire screen) will be announced at the same time as the iPhone 6.