Sapphire, a mineral twin of ruby, is also a crystallised form of corundum, with colors ranging from blue to orange, through green, right down to yellow and pink, but it lacks a few chrome atoms to acquire the red color of ruby. 
The attraction of sapphire comes from its celestial color harbouring much symbolism. This stone adorned the headdress of Kings or the talisman of Emperors. 
Sapphire deposits are found in Myanmar, Thailand, Australia, Sri Lanka, etc.