Velvety blue. Liquid blue. Evening-sky blue. Cornflower blue. Sapphire, beloved for centuries as the ultimate blue gemstone. The ancient Persian rulers believed that the earth rested on a giant sapphire and its reflection colored the heavens blue. Indeed, the very name in Latin, "Sapphiru," means blue.
But like the endless colors that appear in the sky, sapphire is also found in many, many other shades besides blue, from the gold of a sunrise, to the fiery reddish-orange of sunset, to the delicate violet of twilight. Sapphire may even resemble the pale white gloaming of an overcast day. These diverse colors are referred to as "fancy" color sapphires.
A gift of a sapphire symbolizes a pledge of trust and loyalty. It is from this tradition that sapphire has long been a popular choice for engagement rings. More information about Sapphires can be found here.
COLOR: Every color but red
REFRACTIVE INDEX: 1.762 to 1.770
BIREFRINGENCE: 0.008 to 0.010
SPECIFIC GRAVITY: 4.00
MOHS HARDNESS: 9
-Source AGTA, GIA