More on spar from Infoplease:

• Iceland spar - Iceland spar Iceland spar, colorless variety of crystallized calcite, characterized by its ...
• fluorite - fluorite fluorite or fluorspar, mineral appearing in various colors, e.g., green, yellow-brown, ...
• calcite - calcite calcite , very widely distributed mineral, commonly white or colorless, but appearing in a ...
• gypsum - gypsum gypsum , mineral composed of calcium sulfate (calcium, sulfur, and oxygen) with two ...
• barite - barite barite , barytes[New Lat., from barium], or heavy spar,a white, yellow, blue, red, or ...

See more Encyclopedia articles on: Mineralogy and Crystallography