It is softer than sapphire and can be scratched by more materials including keys.
The Sport's screen is made from Ion-X glass, unlike the Apple Watch and premium-priced Edition which have sapphire screens.
In China, though, Jun has almost rockstar status, product unveilings are shrouded in mystery and rumours – before the latest phones were released, some suggested (wrongly) they would have expensive sapphire screens – and thousands of excited fans pack the venues.
With his mother's sapphire and diamond engagement ring prominent on Kate's wedding finger in the first photographs of his daughter, William seldom passes up an appropriate opportunity to keep alive memories of the mother he lost in a car crash when he was 15.
The high-end "Edition" model with an 18-carat gold case and sapphire screen will cost upwards of £8,000 [$10,000], with only limited numbers available.
Sandpaper should not be able to scratch sapphire screens, as silica is a softer material than sapphire.
Viewed from a distance, the JAR sapphire earclips might be a pair of especially gaudy Christmas baubles, while legend has it that the ping-pong diamond rings were Taylor's reward for besting Burton in a game of table-tennis.
His conclusion is that their tails could be composed of either of iron-rich silicates or of corundum a substance that, when of gem quality, is better known as sapphire.
A gallium nitride LED on sapphire has a typical internal quantum efficiency of around 70%.
The purity of the stone and the shield-like shape that forms its front give the sapphire ring the kind of cool elegance that can be reproduced in photographs.
Desperate not to lose a sale, local jewellers lend a small piece of the sapphire to their regular customers to literally sleep over it: they put it under a pillow to check if they are then harassed by bad dreams.
