Approx 14x5cm Quartz is your master healer, it is known as the stone of power and amplifies any energy or intention. It's a wonderful tool to clear the mind of negativity, and open you up to channel divine energy. This piece truly is a supreme gift of Mother Earth. Quartz belongs to the trigonal crystal system, it has a hardness of 7 on the Mohs scale, and is a mineral which is composed of one part silicon and two parts oxygen. It is silicon dioxide (SiO2).