Quartz crystal is one of the most abundant minerals in the Earth's continental crust composed of silicon and oxygen. It is the most powerful healing and energy amplifier. Associated with love, the heart and beauty, and is thought to be a healing aid for the heart chakra. Imbalances of this chakra have been said to cause colds, allergies and psychosomatic illnesses. When in balance, the heart chakra is thought to make one open to love and compassion. Some believe that rose quartz has calming effects and helps people develop strong friendships.