Tectosilicates, or “framework silicates,” have a three-dimensional framework of silicate tetrahedra with SiO2 in a 1:2 ratio. This group comprises nearly 75% of the crust of the Earth.
Silicate mineral (Wikipedia) Silicate minerals are rock-forming minerals made up of silicate groups. They are the largest and most important class of minerals and make up approximately 90 percent of Earth’s crust.