Tourmaline is the most colorful of all gemstones. It occurs in all colors, but pink, red, green, blue and multicolored are its most well-known gem colors. Scientifically, tourmaline is not a single mineral, but a group of minerals related in their physical and chemical properties. The mineral Elbaite is the member of the Tourmaline group that is responsible for almost all the gem varieties. Three other members of the group - Schorl, Dravite and Liddicoatite, are seldom used as gemstones.
Topaz makes an ideal gem. A good hardness and desirable colors, combined with a relative abundance and availability makes it one the most popular gemstones. The most valuable colors of Topaz are the golden orange-yellow type, called Imperial Topaz, and the dark pinkish-red and orange-red colors. Value increases with a deepness of color in orange and reddish hues. The most commonly used colors of Topaz in jewelry are the blue types.
Sunstone is an interesting feldspar gemstone with a glittery appearance and usually an orange or reddish color, hence its name. The glitter effect is caused by inclusions of the mineral Hematite, or sometimes also Goethite or Pyrite (and in one rare instance, Copper). The term used to describe the glittery effect exhibited on Sunstone is aventurescence.
Tanzanite is the blue to violet gem variety of the mineral Zoisite. Since its relatively recent discovery in 1967, it has become a mainstream and popular gemstone, and is used extensively in jewelry. To date, Tanzanite is found only in the Arusha region of the African country of Tanzania, and it was named after its country of origin.