SAPPHIRE

SAPPHIRE IS A PRECIOUS GEMSTONE (A TYPE OF CORUNDUM) THAT RANGES IN COLOUR FROM BLUE TO PINK TO YELLOW TO GREEN TO WHITE TO PURPLE (MAUVE SAPPHIRE) TO PINK-ORANGE (PADPARADSCHA SAPPHIRE). SIX-SIDED ASTERISMS SOMETIMES OCCUR IN STAR SAPPHIRES (CAUSED BY INCLUSIONS OF TINY, THIN, PARALLEL NEEDLES OF RUTILE). SAPPHIRES ARE RELATED TO RUBIES. SAPPHIRE HAS A HARDNESS OF 9 AND A SPECIFIC GRAVITY OF 3.9 – 4.1. SAPPHIRES ARE OFTEN HEAT TREATED TO IMPROVE THEIR COLOUR.