If you plan on going on the Bishop’s Cap hike this Sunday, it will be worthwhile to learn a few things about Fluorite (Fluorspar) CaF2. Fluorite can be used:
To manufacture HF acid which is used to manufacture refrigerants, herbicides, pharmaceuticals, aluminum, plastics, and electrical components
To manufactdure specialty glass, ceramics and enamel wear
To manufacture lenses
To make ornamental objects and jewelry
HF is poisonous and their use by refineries has made it a target of environmental groups. Two technologies have been developed to replace the use of HF: ionic liquids (see article on Chevron) and solid acid catalyst. Learn more.
Read more about the HF controversy: