Calcite

Calcite: a colorless or white mineral consisted mostly of Calcium carbonate (CaCO3)

Although it is in no way a rare or uncommon mineral, calcite piqued my interest the moment I spotted it on the webpage. It is a major component of limestone and dolomite. Limestone has applications in construction and industry where it can be used for road construction, as a filter stone, glass manufacturing, sugar processing, and even acid water treatment.  I also picked calcite because I have always been fascinated with marble as a material. The fact that marble can be equal parts aesthetically pleasing as well as inherently useful ( e.g. for things like countertops) always seemed very interesting to me.