Quartz crystal approx 3cm high
Inside Acrylic Dome approx 7cm high

Quartz top prism showing typical charteristics of the six sided point.

Quartz is one of the most common minerals in the Earth's continental crust. It belongs to the hexagonal rhombohedral crystal system, and is made up of silica (SiO2) tetrahedra. Quartz has a hardness of 7 on the Mohs scale. Density is 2.65 g/cm³. The typical shape is a six-sided prism that ends in six-sided pyramids, although these are often twinned, distorted, or so massive that only part of the shape is apparent from a mined specimen.