The Mineral Wollastonite



Wollastonite mineral is a calcium inosilicate, which may contain small amounts of magnesium, Iron and Manganese, substituting for calcium. Properties of the Wollastonite mineral which make it useful are its high brightness and whiteness, low volatile content, low moisture and absorption. Wollastonite is a common mineral in contact with metamorphic rock or skarns (Wiki description – “calcium-bearing silicate rocks of any age"). It has no useful elements. It forms as a result of the interaction of limestone, (which contains calcite, with silica), in hot magma. Wollastonite has many unique characteristics that enhance its use in the industry. It increases the performances of many products like construction material, plastics, paints and coatings. It helps in advanced processing.

Chemical Formulae
CaSio3.

Occurrence
Deposits of Wollastonite minerals are found in California, Arizona, Nevada, New Mexico and Utah, New York. These deposits contain Calcite, Garnet, Diopside, Quartz, Idocrase as minor components of Wollastinite and Skarns contain Wollastonite as a major ingredient. In Skarn, Wollastonite can be produced in diffusion reaction.

Derivation Of Name
Wollastonite mineral is named after the British mineralogist and chemist William Hyde Wollaston (1766-1828). Its original mineralogical name was wollastonit 1T. (1T standing for triclinic symmetry). The rarest form of Wollastonite is Wollastonite -2M, known as “Parawollastonite", which is monoclinic

Uses
Wollastonite mineral is mainly used in friction products, metal making, ceramics, paint filter and plastics. It is mostly used in tile factories and industries all over the world, and in the manufacture of plastics and paper. In plastics, the needle-like structure of wollastonite improves the durability of the composite. In paints and coatings the alkaline nature and secular structure of wollastonite make them perfect as auxiliary pigment in industry primers and coating for improving corrosion resistance. Wollastonite is used as a substitute for asbestos in building products in the construction industry as a fire resistant ingredient. One can also use this mineral in ceramic products including fluxes, sanitary ware, ceramic glaze, enamels and Frits.

Physical Characteristics

Color
White, gray or without color

Luster
Vitreous or dull to pearly on cleavage surface

Transparency
Crystals are translucent and rarely transparent.

Crystal system
Triclinic

Cleavage
Ideal in two directions

Hardness
5-5.5

Streak
White

Fracture
Splintery to uneven.

Specific gravity is
Approx. 2.8-2.9

Best Field Indicators
Cleavage, solubility in HCL, crystal habit, softness and fluorescence

Associated minerals
Tremolite, Diopside, Andradite, Epidote and Vesuvianite

Contact Us
Home | Contributers | Policies | Links | Story of Our Name |  FAQs Why the Ads?  ¦   How Can I Help?   ¦  © LearnAboutNature.com