Quartz is the earth's most common mineral. It is found throughout the world and makes up approximately 12% of our crust. With a hardness of 7, quartz is tough enough to resist weathering and is commonly found in alluvial sands and gravels.
Rutilated quartz is named for the needles of rutile which have crystalized within the mother rock. Rutile is the most common natural form of titanium dioxide (TiO2), and it forms in long needle like crystals. The needles can be oriented quite randomly, or in specific directions related to the crystallography of the host.