Inosilicate

inosilicate, formerly called metasilicate, any of a class of inorganic compounds that have structures characterized by silicate tetrahedrons (each of which consists of 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).