Quartz JewelryWhere the name comes from: Derived from the German word quarz - hard.
Where the stones come from: Quartz is the second most abundant mineral on earth (after feldspar), gem quality deposits however are much less common though widespread across the world.
Chemistry: Silicon dioxide., SiO2
Colors: A number of other gemstones are forms of quartz such as agate, citrine, chalcedony, onyx, jasper, carnelian.
...and another thing: In 1927 the first clock was made with a quartz crystal as a means of keeping time, quartz clocks are an order of magnitude or greater more accurate than a mechanical clock.