Sapphire is most desired in its pure, rich blue color but is present in almost every color including pink, yellow and green. With a hardness closest to diamond, these stones are my personal favorites for life long wear!

Identification

Color - Blue sapphires range from very light to very dark green-blue or violet-blue, as well as various shades of pure blue. The most prized colors are a medium to medium dark blue or slightly violet-blue. 

Sapphire is a variety of the gem species corundum and occurs in all colors of the rainbow. Pink, purple, green, orange, or yellow corundum are known by their color (pink sapphire, green sapphire). Ruby is the red variety of corundum. - American Gem Society

Mohs Hardness - 9

History

Traditionally, 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.
 
For centuries, sapphire has been associated with royalty and romance. The association was reinforced in 1981, when Britain’s Prince Charles gave a blue sapphire engagement ring to Lady Diana Spencer. Until her death in 1997, Princess Di, as she was known, charmed and captivated the world. Her sapphire ring helped link modern events with history and fairy tales.
 
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. - GIA

Physical, Mystical and Spiritual Properties

Today Sapphire is still a Stone of Wisdom, a royal stone of learning, mental acuity and psychic activation, a seeker after spiritual truth. Its pure Blue Ray brings order and healing to the mind, lending strength and focus, and an ability to see beneath surface appearances to underlying truths and to utilize that knowledge.

It stimulates the Throat and Third Eye Chakras, allowing one to access deeper levels of consciousness in order to gain a fuller understanding of self. Associated with the planet Saturn, Blue Sapphire embraces order, structure, and self-discipline, and is ideal for accomplishing goals and manifesting ideas into form. Sapphire’s power to transmute negative thoughts and energy also makes it highly effective for earth and chakra healing. - Crystal Vaults