Quartz - the most popular of all the crystal healing stones, is the second most abundant mineral on the planet, so abundant that almost every rock in the world contains traces of it 

Healing Healing and Metaphysical Tradition : Known as the Master Healer. Thought to amplify, focus, store and transfer energy while clearing blockages and dissipating negative energy. Also thought to stimulates the memory and clear the mind. Traditionally associated with chronic fatigue, arthritis, bone injuries, depression, diabetes, fibromyalgia, and intestinal troubles.

Cool facts: It  is used to make the internal parts of watches and to make many computer components. People in Ireland and other countries used quartz to make stone tools in prehistoric times.