David Adamson Designer Jewelry

Quartz is one of the most common minerals on earth and is well known in the gems world. Quartz is attractive and durable, as well as inexpensive. It can be cut and carved in many forms and sizes. Quartz is named after a Slavic word for "hard".

There are two main varieties of quartz, though they share the same chemical composition, silicon dioxide. Macrocrystalline quartz and Crytocrystalline quartz.

The colors of macrocrystalline quartz are as follows:

Rock crystal: Colorless. Material that can be cut is rare. Inclusions are of goethite, gold, pyrite, rutile or tourmaline. The luster is vitreous.

Smoky quartz: Brown to black, smoky gray. The coloring is caused by natural and artificial gamma rays. Frequent inclusions are rutile needles.

Amethyst: Purple, violet, pale red-violet. Amethyst is the most highly valued stone in the quartz group. The coloring agent is iron.

Ametrine: Yellow and violet. Color-zoned quartz variety that consists half of amethyst and citrine.

Citrine: Light yellow to dark yellow, gold-brown. The coloring agent is iron. Many commercial citrines are heat-treated amethyst. Natural citrines are mostly pale yellow. If heat-treated they acquire a reddish tint.

Prasiolite: Leek-green. Prasiolite is not found in nature. Prasiolite is produced by heat treatment of amethyst or yellowish quartz.

Rose quartz: Strong pink, pale pink. Coloring agent is titanium. Traces of included rutile needles cause six-rayed stars when cut en cabochon. Larger clear stones can be faceted. Rose quartz crystals tend to be cloudy, which deepens the color. Transparent crystals are extremely rare.

Tiger's eye: Gold-yellow, gold-brown (ray of light is brown colored due to oxidized iron inclusions)

The colors of Cryptocrystalline quartz:

Agate is distinguished by having multiple colors. Banded agates are some of the most popular.

Fire agate: The iridescent colors of red, gold, green and rarely, blue-violet, result from interference between light rays traveling through these thin layers.
Bloodstone is an opaque, dark-green chalcedony with red spots (caused by iron oxide).

Chalcedony, in the narrow sense, comes in bluish white or gray. Unicolored chalcedony sometimes is called onyx.

Carnelian ranges in color from yellow-orange to rich, near reddish orange, to orangey brown, and varies from semi-opaque to highly translucent. The color agent is iron. The color can be enhanced by heating. Cornelian onyx is a layer stone with a red base and a white upper layer.

When Buying Quartz
You want to look for the deepest and richest colors as these are the most valuable.

World-famous Quartz
Chrysoprase, the bright apple green translucent chalcedony, was a particular favorite of Frederick The Great of Prussia. It can be seen today decorating many buildings in Prague, including the Chapel of St Wencelas.

Fine amethysts are featured in the British Crown Jewels and were also a favorite of Catherine the Great and Egyptian royalty. In former days amethyst was a favorite stone in the high ranks of the Christian church, therefore it was called "the stone of bishops".

One of the finest known rock crystal pieces is the 12.75 inch diameter, 107 pound flawless "crystal ball" in the collection of the Smithsonian Institution in Washington D.C.

So whether you love amethyst, topaz, citrine, etc remember that all of these – and many more – are all in the Quartz family and are a magnificent addition to any jewelry collection.

Happy Quartzing