Quartz and Quartzite are two examples of minerals, and they are very much available in abundance on the earth crust. Although their names might look similar, there are still some differences between them. Quartz has the chemical composition of silicon dioxide (SiO2). You can as well say, quartz is made up of silica and oxygen. Quartzite, on the other hand, is a metamorphic rock that consists of interlocking particles of quartz.
In terms of abundance in nature, quartz is the most occurring out of the two, and it is very much available virtually every part of the world. Quartz occurs in a variety of ways; for example, it can occur as a crystalline solid and amorphous, while Quartzsite exists only as metamorphic. Both quartz and Quartzite and very useful. While quartz is used as gemstones and also as materials in electronics, Quartzite is used mostly in flooring tiles and as a roofing material, and it is useful in construction works generally.