They are divided into two groups: the transparent crystalline varieties and the translucent to opaque chalcedonies that are microcrystalline forms of quartz. There are many different varieties in these two types but they have one thing in common: they are low in cost. Some are downright cheap! Quartz is one of the most abundant minerals on the earth's crust.

The queen of the quartz, Amethyst is most expensive of the quartzes. Amethyst ranges from pale to dark violet. The finest qualities of Amethyst are a medium dark violet with a strong secondary red color. Darker shades of Amethyst may appear slightly differently under different light sources. Amethyst is available in all sizes and shapes. Light Amethyst will be very low in per carat prices with the finest qualities still well under US$l00 per carat. Darker Amethyst of any size will have color zoning. This may not be visible without extensive examination. Often the zoning consists of areas of red violet and areas of blue violet, this combination can enrich the appearance of the stone. Sometimes the zoning is easily visible and detracts from the beauty of the stone.

The bi-color variety, Ametrine is part Amethyst colored and part Citrine colored. It was first discovered in Bolivia. Generally Ametrine is cut into octagon or emerald cut shapes to emphasize the two colors. Ametrine has been carved into some very interesting gem art works. Prices will start in the low end and go to moderate price per carat.

The quartz without color, also called "rock crystal" simply lacks interest as a jewellery stone. Even when it is well cut it lacks brilliance. Occasionally it will contain some interesting inclusions that can increase its appeal. Colorless quartz is occasionally found with rutile needles inside, which look like long golden threads, sometimes arranged in a pattern. This is called Rutilated Quartz and is popular in art jewellery. Most gold bearing quartz is milky white rather than transparent.

Smoky quartz is brown transparent quartz of all shades; it generally has a slightly grayish cast. Prices should always be very inexpensive.

Quartz can be made into beads and have been popular for a hundred or so years; these are often faceted into appealing shapes. Tiger's eye is quartz with asbestos inclusions; this gives it a subtle silky appearance. Generally it is golden to brown in color; it can also be dyed. Blue material is called Crocidolite. Star quartz is a fascinating stone; the quartz may be colorless or pink. The stars are six-rayed and roll around the stone as it is moved.