Set of Rock Crystals Quartz 100 g

• Total mass: 100 gramms
• a crystal size: 15-35 millimeters
• crystal mass: 1-3 gramms
• Confirmed with gemmological experise

Natural rock crystal weighs 100 grams. Crystal weight is 1-3 grams. Size is 1.5-3.5 cm. There is a gemological examination report from the Assay Office. Ancient Greek philosophers believed that rock crystal is ice turned into stone. That is where the name crystal comes from, from "kristallos" - like ice. It has low thermal conductivity, so crystal crystals are always cold to the touch, which distinguishes them from glass. Quartz is a hard, crystalline mineral composed of silica (silicon dioxide). The atoms are linked in a continuous framework of SiO4 silicon–oxygen tetrahedra, with each oxygen being shared between two tetrahedra, giving an overall chemical formula of SiO2. Quartz is, therefore, classified structurally as a framework silicate mineral and compositionally as an oxide mineral. Quartz is the second most abundant mineral in Earth's continental crust, behind feldspar.