Iolite: This silicate mineral (cordierite) can occur as crystals or grains in igneous rocks, as a result of aluminous sediment in magma. Also known as water sapphires, dichroite, Spanish lazulite, and Vikings' compass, the transparent purple-blue variety of this stone is iolite, named after the Greek word for violet, ios. Iolite beads and stones are known for their extreme pleochroism, or ability to change colors depending from which angle you look at them. While this semiprecious gemstone has a nice Mohs hardness of 7-7.5, it should be protected from harsh blows due to its distinct cleavage in one direction. This lovely purple gemstone is said to open and expand psychic talents, and is supposed to be excellent for use on the third eye and crown chakras. It also is believed to enhance curiosity, stimulate visions, and help the wearer deal with addictions, including alcoholism (assisting in detoxification as well as maintaining sobriety). Not always available.