Quartz (SiO2) is one of the most common minerals in nature forming hexagonal columnar crystals finished with planes of trapezohedron or dipyramid. Crystal planes are frequently grooved.  The crystals can be found in a form of crystal twinning and other various deformations. However, this mineral usually has massive, granular or microcrystalline shape, and can be also found as amorphous. It can be of various colours, virtually covers the whole colour spectrum. Its streak is white.  Quartz is a transparent even translucent mineral with vitreous shine on a new surface. Plenty of its forms represent semiprecious stones, for instance: clear crystal quartz...