Constituents of quartz are silicon and

Minerals are classified by their chemical composition — the specific elements that combine, in fixed proportions fixed by the mineral's chemical formula, to form the compound.

Quartz is one of the most common minerals in Earth's crust and is chemically defined as silicon dioxide, SiO2. Its formula shows it is composed of exactly two elements — silicon (Si) and oxygen (O) — combined in a 1:2 ratio, forming a continuous framework of SiO4 tetrahedra. So the constituent alongside silicon is oxygen.

This matches the general rule for silicate minerals, which are built from silicon-oxygen (SiO4) tetrahedra as their fundamental structural unit — sulphur, nitrogen, and hydrogen do not appear in this structure.

• Sulphur (S) forms compounds such as sulphur dioxide (SO2) and pyrite (FeS2), not quartz.

• Nitrogen (N) is a major atmospheric gas (N2) and does not occur in the silicate mineral framework.

• Hydrogen (H) occurs in hydrous minerals as hydroxyl groups, but is not part of quartz's SiO2 formula.