Quartz is a mineral composed of silica, with the chemical formula SiO2. Pure quartz is colorless and transparent, and exhibits various colors due to the presence of trace pigment ions or finely dispersed inclusions, or the presence of color centers, which reduces the transparency. With vitreous luster, the fracture is oily luster. Hardness 7, no cleavage, conchoidal fracture. Specific gravity 2.65. Piezoelectric.
