Amethyst: Emperor of Quartz

February’s birthstone amethyst, is the most prized variety of the quartz family.

February's Birthstone Amethyst

Although once only available to royalty, amethyst’s plentiful supplies have made it widely available to the general public.

Amethyst, the gemstone believed by ancient Greeks and Romans to ward off the intoxicating powers of Bacchus (wine), also is said to keep the wearer clear-headed and quick-witted.

Throughout history, the gemstone has been associated with many myths, legends, religions, and numerous cultures. English regalia were even decorated with amethysts during the Middle-Ages to symbolize royalty.

Amethyst Color Range

This photo shows the gem’s possible color range. (photo: Pala International)

Quartz is one of the most abundant minerals in the Earth’s crust. It is composed of the elements silicon and oxygen and in its pure state is colorless. Small amounts of various impurity atoms can produce a range of colors in quartz. Amethyst, the most valuable gem variety of quartz, is purple.

Today, because of its availability and affordability, it is used in mass-market jewelry as well as custom designer pieces. This makes amethyst one of the world’s most popular colored gems and the most commercially important gem-quality quartz variety.

Today’s major sources are Brazil, Bolivia and Uruguay in South America and Zambia in Africa. Brazilian stones can be found in huge sizes, but generally are moderate in color. They often suffer from color-banding, which sometimes is visible despite efforts of the cutter to minimize it.

Amethyst Color Banding

Color-banding in amethysts lowers the value of these stones.

African material, especially from Zambia, can be a highly saturated raspberry color. It tends to have more inclusions than Brazilian material. However, due to its remarkable color, this is considered acceptable in a faceted stone.

Many stones display a weak, light color or have strong zones of lighter and darker purple color known as color-banding. These factors lower the value of these stones. Color banding is most visible when an amethyst is viewed face-down through its pavilion on a white background. It’s not as visible face-up.

Amethyst is cut into a variety of standard shapes and cutting styles. These include rounds, ovals, pear shapes, emerald cuts, triangular shapes, marquises, cushions, and others.

Facet patterns include the classic triangular and kite-shaped facet arrangements called brilliant cuts, rows of concentric parallel facets called step cuts, and mixed cuts that combine both facet arrangements.

popular cuts

Amethyst is produced in a variety of popular cuts. (photo: John Miatech)

Value per carat in amethyst, unlike many gems, doesn’t rise exponentially with weight as it is readily available in large sizes; but depends almost entirely on color. The “Siberian” deep purple with red and blue flash commands the highest prices. As the stone is plentiful, there is little reason to pay top dollar for stones with visible inclusions or inferior cutting.

Amethyst is occasionally heat-treated to lighten the color of very dark amethyst, and to remove the smoky component of color. The heat treatment is very stable and is undetectable.

Due it’s hardness of 7 and a toughness rating of good, amethyst is a perfect stone for everyday wear. It also means that it is usually safe to clean amethyst in an ultrasonic cleaner, unless the stone is heavily included.

warm soapy water

Clean in warm soapy water and a soft toothbrush (photo: Eric Welch)

Cleaning with warm soapy water and a soft toothbrush are the safest way to keep your amethyst looking it’s best.

We hope you found this article helpful in getting a better understanding on amethyst. However, should you have any additional questions about this or any other jewellery related topics, you can always: “Ask the Jeweller”

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This article was compiled from my personal knowledge as a gemologist, as well as numerous online sources, individuals and textbooks. If you have something to add to this article that you feel would be of benefit to others, please, do not hesitate to contact us.