Sapphire is gem corundum of any color except the red that is called ruby. The mineral is still aluminum oxide, Al2O3, trigonal, hardness 9. Blue sapphire is the familiar color, often from iron and titanium, but natural sapphire is also yellow, green, pink, purple, orange, and colorless.
Padparadscha is a pink-orange sapphire, not a separate mineral. Star sapphire shows asterism from oriented rutile needles. Crystal habit is the same hexagonal, often barrel-shaped form as ruby.
This page is only for sapphire. Ruby has its own page because collectors treat the red variety separately, even though both are corundum.