Of Sapphires and Rubies here is a little info.
Historically, the finest and most vibrant gem-quality sapphires have come from Sri Lanka, Burma and the Kashmir region of India. Sapphires from Sri Lanka are typically light to medium blue and are commonly referred to as “Ceylon Sapphires.”
All sapphires are made of the mineral corundum (crystalline aluminum oxide). In its pure state, the corundum is colorless, but when trace elements are naturally introduced to the chemical composition, all the magic happens. Blue sapphires occur, for instance, when aluminum atoms are displaced with those of titanium and iron in the gem’s crystal lattice structure. Corundum has a hardness of 9 on the Mohs scale, compared to a diamond, which has a hardness of 10.
Sapphires are seen in many colors, including pink, purple, green, orange and yellow. Ruby is the red variety of corundum.