Sillimanite or fibrolite is an aluminosilicate mineral with the chemical formula Al<sub>2</sub>SiO<sub>5</sub>. Sillimanite is named after the American chemist Benjamin Silliman (1779–1864). It was first described in 1824 for an occurrence in Chester, Connecticut.
Sillimanite has been found in Brandywine Springs, New Castle County, Delaware. It was named by the State Legislature in 1977 as the state mineral of Delaware by the suggestion of the Delaware Mineralogical Society.
Uses
Natural sillimanite is used in the manufacture of high alumina refractories or 55–60% alumina bricks. However, it has mostly been replaced by the other aluminosilicate polymorphs, andalusite and kyanite, for this purpose. , sillimanite was just 2% of all aluminosilicate mineral production in the western world.
Gallery
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File:Sillimanite.jpg|Silimanite crystal from Sri Lanka
File:Fibrolite.JPG|Fibrolite micrograph
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See also
- List of minerals
- List of minerals named after people
- Asbestos cement, which is also called "fibrolite"