# How does silica affect the color of igneous rocks?

Dec 20, 2015

Pure silica has the chemical formula $S i {O}_{2}$ - silicon dioxide. Glass is silica that has an amorphous structure, which means the silicon and oxygen atoms aren't in a repeating lattice. Quartz is the form that pure silica takes in nature. It has a tectosilicate structure, which means the atoms form a lattice of tetrahedra bonded together.