Rock Crystal is a colourless form of quartz, and sometimes comes with rutile inclusions. Crystal is from the Greek word "Krustallos" which means ice. The crystal angle is related to the golden number. Greeks and Egyptians already used it for their constructions, Cheops pyramid being a prime example. Its energy is endless as it constantly captures it from the universe. A sacred stone, it opens the consciousness of the wearer, it is a stone of clairvoyance, wisdom and healing. It is the most widely used stone in lithotherapy, both on the physical and psychic level. It strengthens the action of other stones. A stone of light, it displays the colours of the rainbow. It is the mother stone, soothing, healing and protecting. Easy to program, it can be a precious ally. It is a great gift for a 15th wedding anniversary. Nowadays it is at the forefront of technology: quartz crystals are used in watches, clocks, computers, transceivers, radios, TVs, etc. It is a bridge between heaven and earth, immaterial and material world.