Blue Sapphire

Color:   Baby blue to vivid blue to midnight blue
Gem Family:   Sapphire is a member of the corundum family, which includes both ruby and sapphire. Sapphire is available in every color but red, which is ruby, but most people think of sapphire first as the ultimate blue gemstone.
Source:   Blue sapphire is mined in Sri Lanka, Madagascar, Australia, Kashmir, Burma, Thailand, Cambodia, Tanzania, Kenya, and the United States.
Clarity:   Ranges from no visible inclusions to moderately included.
Size Range:   Small accent stones to spectacular 10-carat gems. Exceptionally rare large stones have been found in sizes larger than 200 carats.
Shapes Available:   Most available in oval and cushion shapes. In smaller sizes, sapphire is also available in a variety of shapes including brilliant and Portuguese rounds, emerald cuts, princess cuts, and trillions.
Enhancement:   There are completely natural sapphires but most sapphires are heated to maximize the beauty of their inherent color and improve clarity. Heat enhancement is stable, routine, and does not require special care. There are now also sapphires treated by bulk diffusion, which have additional elements diffused into the surface to artificially improve their color. Sapphire treated by bulk diffusion is far less costly and much more available than rare fine natural gems or those successfully heat-treated.
Lore & History:   Sapphire comes from the Greek word for blue, sappheiros, and this gem provides the most beautiful blues of the gem kingdom. The ancient Persians believed the earth rests on a giant sapphire. Its reflection, they said, made the sky blue. Sapphire is the original "true blue": the gem of fidelity and of the soul. In ancient times, a gift of a sapphire was a pledge of trust, honesty, purity, and loyalty. This tradition makes sapphire a popular choice for engagement rings. Sapphire is the birthstone for September and the traditional gift for the fifth anniversary.
Toughness & Hardness:   Sapphire has a hardness of 9 on the Mohs scale and it is quite tough. Only diamond is harder.
Care & Cleaning:   Sapphire is among the most durable gemstones. In its common form, corundum is even used as an abrasive! Clean your sapphire with warm water, detergent, and a soft brush. Sapphire can be put in ultrasonic or steam cleaners.
Special Characteristics:   Sapphire is so hard you must cut it with sapphire or diamond. Diamond powder creates the best polish and sparkle.