95 articles
Witherite
Witherite is a rare barium carbonate mineral, BaCO₃, of the aragonite group, historically mined almost exclusively in northern England as the world's principal source of barium carbonate.
Wolframite
Wolframite is an iron-manganese tungstate mineral, (Fe, Mn)WO₄, occurring as a series between ferberite and hübnerite; it is the primary ore of tungsten, mined commercially alongside scheelite.
Wollastonite
Wollastonite, calcium metasilicate (CaSiO3), is a white calcium silicate mineral with needle-like crystals, named for Sir W.H. Wollaston and used in ceramics, plastics, paint, and metallurgy as an asbestos substitute.
Xenotime
Xenotime is a rare-earth phosphate mineral, the yttrium orthophosphate end member of the xenotime group, one of the three principal rare-earth ores and an important source of heavy rare earths.
Zircon
Zircon, also known as zirconium orthosilicate, is a natural zirconium silicate mineral, ZrSiO4, the principal source of zirconium and hafnium and a gemstone prized for its fire.