Natural quartz is found in many countries and geologic locations, including the United States, Mexico, Brazil, Uruguay, Russia, France, Namibia and Morocco. Quartz is the second-most abundant mineral in the Earth's crust, and different types of quartz are found in different areas of the world.
Natural quartz is used mainly in jewelry, while cultured quartz is used in electronic applications. The varieties of natural quartz most often used in jewelry are rose quartz, citrine, amethyst, smoky quartz, milky quartz and rock crystal. Each type of quartz ranges greatly in color.
Rose quartz has a soft pink to rose-red hue. Most rose quartz comes from Brazil. Citrine quartz ranges in color from a very pale yellow to brown. Brazil is the largest producer of citrine quartz. Amethyst ranges in color from a bright to dark purple hue. The world's largest amethyst deposits are found in Mexico, Brazil, Morocco, Russia, Uruguay, Namibia and France.
Smoky quartz is grey or brownish-grey and somewhat translucent in color, but it can also be black. Smoky quartz is found in the United States, Brazil, Switzerland, Madagascar and Scotland. Milky quartz is a white cloudy color. It is the most abundant type of quartz and can be found almost anywhere in the world. Rock crystal quartz is translucent, and it may be called pure quartz or clear quartz.