While quartz is one of the most abundant minerals on the Earth's surface, it makes it no less valuable, or beautiful! It is composed of the elements silicon and oxygen, and in its pure state it is colorless, though just small amounts of various impurity atoms can yield a variety of colors. It is common to find inclusions in quartz crystals. Quartz is usually one of the last minerals to form in a deposit, so it sometimes grows around existing crystals. Because quartz is commonly clear, the inclusions are easy to see, as seen in smokey and rutilated quartz.