Sapphire symbolizes nobility, truth, sincerity, and faithfulness. It has decorated the robes of royalty and clergy members for centuries. Its extraordinary color is the standard against which other blue gems—from topaz to tanzanite—are measured.
In ancient Greece and Rome, kings and queens were convinced that blue sapphires protected their owners from envy and harm. During the Middle Ages, the clergy wore blue sapphires to symbolize Heaven, and ordinary folks thought the gem attracted heavenly blessings. In other times and places, people instilled sapphires with the power to guard chastity, make peace between enemies, influence spirits, and reveal the secrets of oracles.
In folklore, history, art, and consumer awareness, sapphire has always been associated with the color blue. Its name comes from the Greek word sappheiros, which probably referred to lapis lazuli. Most jewelry customers think all sapphires are blue, and when gem and jewelry professionals use the word “sapphire” alone, they normally mean “blue sapphire.”
Source : www.gia.edu