tectosilicate

The basic structural unit of all silicate minerals is the silicon tetrahedron in which one silicon atom is surrounded by and bonded to (i.e., coordinated with) four oxygen atoms, each at the corner of a regular tetrahedron.

tectosilicate, any member of a group of compounds with structures that have silicate tetrahedrons (each of which consists of a central silicon atom surrounded by four oxygen atoms at the corners of the tetrahedron) arranged in a three-dimensional lattice. Each of the four oxygen atoms of a given tetrahedron is shared with another tetrahedron. Each tetrahedron, therefore, is linked to four others. Tectosilicates, including quartz and other silica minerals, have chemical formulas that contain some multiple of SiO₂.