Blue Barite from Sterling, Colorado. Barite is a wonderful mineral these blues being highly prized as well as the amber yellow crystals.
Barite is a very common mineral in the earth's crust. It is the crystals which are rarer. Well formed macroscopic crystals, in the geological perspective, are rare indeed. Think about it, how often do you walk about and come across a euhedral crystal (
Geology Definitions - Geological Dictionary - Earth Science