Blue minerals
Sparkling sapphires are probably the best known blue minerals. Sapphires are a precious form of the mineral corundum - second only to diamond in hardness. But although we all think of sapphire as being blue, it can be lots of other colours as well - yellow, green, pink, and even colourless - in fact any colour except red. Have a look on the colour wheel to see what red corundum is called.