Close-up of an 18k yellow gold necklace featuring blue sapphire gemstones.

Sapphire Jewelry

A colorful hero of the gemstone world, sapphire is every color of the rainbow (except red, when it's a ruby - together they constitute the corundum mineral species). Sapphire is an excellent choice for an engagement ring because of its hardness, second only to diamond. Sapphire is the birthstone for September.