Chemical Formula: BaSO4
Color: Any color
Importance: The main use of barite is as a source of barium. Barium from barite has a wide variety of uses including as a contrast in digestive system X-rays, oil and gas drilling, paper and rubber manufacturing, and in fireworks to give off a green color.
Other Interesting Information: Some specimens of barite also have fluorescent properties, which means that they glow when exposed to ultraviolet light. Also, special forms of barite can form in a rose shape.
My Take: Unlike other minerals, barite can form in nearly any shape. This causes very beautiful and rare specimens to form, making barite a unique mineral.
For More Information: http://www.minerals.net/mineral/barite.aspx