Sapphire

Sapphire is generally the blue form of corundum however it also includes all other colours (excluding the reds); blue shades from cornflower blue, royal blue through to a very dark blue almost black. Other colours found include green, orange, colourless and yellow. Some have rutile inclusions that appear like fine needles, when these stones are polished as a cabochon they display what is called a 'cats eye' or 'star' effect.