Quartz Crystal

The most common mineral in the Earth's continental crust/Geology & Minerals

Quartz is the second most abundant mineral in the Earth's continental crust, made of silicon dioxide arranged in a continuous framework of SiO4 tetrahedra. A typical collectible quartz crystal point is about 10 cm long and 3 cm wide. Quartz has a hardness of 7 on the Mohs scale and exhibits piezoelectric properties, meaning it generates voltage when compressed. This property makes it essential for watches, radios, and electronic oscillators.