Commonly associated minerals include pyrite, pyrrhotite, galena, sphalerite, fluorite, dolomite, and calcite. Common examples include calcite, quartz, topaz, beryl, tourmaline and fluorite, among others. Its associated minerals include pyrite, chalcopyrite, quartz, anhydrite, fluorite, and scheelite. It is often associated with the minerals sphalerite, calcite and fluorite. Taaffeite occurs in carbonate rocks alongside fluorite, mica, spinel and tourmaline. The initial uranium mineralisation consists of quartz, carbonate, fluorite and pitchblende. Lead is a by-product of fluorite, baryte and calcite mining. In 1833, David Brewster discovered the fluorescence of the mineral fluorite or fluorspar. Sylvite, along with quartz, fluorite and halite, is used for spectroscopic prisms and lenses. Lesser amounts of copper, lead, molybdenum, gold, silver, kaolin, and fluorite also were mined. Natural fluorite mineral has ornamental and lapidary uses. Also contained is zircon, fluorite, and allanite. Mineral resources from the province include iron, coal, fluorite, limestone and tungsten. Fluorite, calcium fluoride, is the state mineral. Fluorite, fluorapatite and cryolite are the most industrially significant.