INOSILICATE

formerly called Metasilicate, any of a class of inorganic compounds that have structures characterized by silicate tetrahedrons (a central silicon atom surrounded by four oxygen atoms at the corners of a tetrahedron) arranged in chains. Two of the oxygen atoms of each tetrahedron are shared with other tetrahedrons, forming a chain that is potentially infinite in length. Single chains (with a multiple of SiO3 in the chemical formula), double chains (with Si4O11 in the formula), and more complex chains are possible. Mineral examples include the pyroxenes (single chain) and the amphiboles (double chain).