Quartz is one of the most common minerals on earth and the quartz family is made up of two separate branches. When most people think of quartz, they think of what is known as macrocrystalline quartz, which includes rock crystal, amethyst, citrine, smoky quartz and rose quartz. Macrocrystalline quartz, as the name suggests, has large crystals which can be distinguished by the naked eye. This type of quartz is mainly transparent to translucent, with a vitreous luster. In practice, the name chalcedony refers to solid colored cryptocrystalline quartz, especially of a light color. The patterned varieties tend to have their own names. The most famous of these include agate, which is distinguished by its bands of color; black and white layered material known as onyx (this is usually dyed to produ.
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