Spar (mineralogy)

Spar is an old mining or mineralogy term used to refer to crystals that have readily discernible faces.

A spar will easily break or cleave into rhomboidal, cubical, or laminated fragments with smooth shiny surfaces.

Amongst miners the term "spar" today is frequently used alone to express any bright crystalline substance.

Most frequently, spar describes easily cleaved, lightly colored nonmetallic minerals such as feldspar, calcite or baryte.

Sometimes, spar will form in the air due to solutions seeping out of the cave's walls or through porous sediments.