Amethyst: Properties, Facts and Photos

Amethyst is the purple variety of quartz and one of the world's most recognisable minerals. This article explores the source of its colour, the meaning of its name, its history and some common misconceptions.

What is Amethyst?

Amethyst is the purple variety of the mineral quartz. Its colour comes from tiny amounts of iron within the crystal structure.

When amethyst crystals are exposed to natural radiation from the surrounding rock over long geological periods, the radiation alters the iron and creates colour centres. These absorb certain wavelengths of light, which makes the crystal appear purple.

Heat destroys colour centres, which is why the colour of amethyst fades or disappears when it's heated. At higher temperatures, the iron changes, causing the crystal to turn yellow.

Because it's so easy to change the colour of amethyst, and with natural citrine being so rare, most commercial-grade citrine is heated amethyst.

In natural amethyst, white quartz or subtle shades of orange or yellow are sometimes visible towards the base of the crystal. This is because there's less iron in the lower section. The colour towards the tip is often much stronger.

It's believed this is because of the mix of iron in the water as the crystal grows.

Prasiolite is a rare green variety of quartz. When amethyst from certain locations is heated, it turns green. This is how most prasiolite is produced. It's often described as green amethyst, which is incorrect.

Amethyst is purple by definition, so quartz of any other colour cannot be amethyst. Heated amethyst that turns yellow is called citrine, not yellow amethyst. Likewise, heated amethyst that turns green is called prasiolite, not green amethyst.

Amethyst was once considered a precious stone, along with diamond, ruby, sapphire and emerald. After huge reserves were found in South America in the 1800s, it became a far more affordable stone. Today, amethyst can be found in many countries around the world, including the United Kingdom.

Meaning of the Word Amethyst

The name amethyst comes from the Greek amethystos, meaning 'not drunk' or 'not intoxicated'.

The name was already in use in the fourth century BC, when Theophrastus described amethyst in On Stones. He calls it wine-coloured but gives no explanation for its name and makes no connection with drunkenness.

The name also appears as amethyston, alongside a ring, in a temple inventory from the Greek island of Delos, dated 250 BC.

Nearly four centuries later, Pliny the Elder discusses the origin of the name in his Naturalis Historia, where he likens the colour of amethyst to wine. He records the Magi's claim that it prevents drunkenness and that this explains its name, but dismisses the claim as false.

The name Magi originally referred to a priestly group in ancient Persia, but Pliny uses it more broadly for practitioners of magic. Throughout his discussion of gemstones, he challenges claims they made about the powers of stones.

Pliny's hostility is clear, and he describes magic as the most fraudulent of arts. He traces its origins to Persia and Zoroaster.

Elsewhere in the same passage, he records that the name amethyst comes from the stone's wine-like colour.

In 2021, archaeologists in Israel found a gold ring set with a large amethyst at the site of a huge Byzantine-era wine-making operation. It was unearthed near a warehouse where wine was stored, in a layer dated to the seventh century AD. The ring may be as old as the third century.

What Colour is Amethyst?

Amethyst, which is one of the world's oldest gemstones, is well known for its rich purple colour. However, the shade can vary significantly.

The finest gem-grade stones have a reddish-purple colour, deep saturation, and no colour zoning. Amethyst crystals in darker shades of purple are also popular, but if too dark, the stone can look almost black.

Purple doesn't exist as a single wavelength of light. It can only be produced by combining red and blue. Therefore, purple is a perceived colour invented by our eyes and brain.

A rainbow exhibits the full spectrum of colours yet doesn't include purple. This short video explains why.

Colours have long been known to affect mood, behaviour and even emotions. Throughout history, purple has been associated with religion, royalty and wealth. Today, it's also associated with magic, mystery and fantasy.

The suffragettes wore purple, white and green, colours chosen by Emmeline Pethick-Lawrence in 1908. She said purple was the royal colour, standing for "the instinct of freedom and dignity"; white stood for purity and green for hope.

Until 1856, the colour purple could only be produced from natural dyes. By the 16th century BC, it was being produced from the mucus of murex sea snails.

Known as Tyrian purple, it was named after the Phoenician city of Tyre, in modern-day Lebanon.

Hundreds of thousands of snails were needed to produce an ounce of dye. In 1909, the chemist Paul Friedländer used 12,000 sea snails to make just 1.4 grams of pure dye, enough to colour the trim of a single garment.

The History of Amethyst

Amethyst has been written about for more than two thousand years. To the ancient Egyptians and Romans, it was valuable and highly sought after.

An amethyst scarab from a tomb at Lisht in Egypt, dated to around 1981 to 1950 BC, almost four thousand years ago, is housed in The Metropolitan Museum of Art. Scarabs were amulets, symbols of creation and rebirth through their link with the sun.

The Book of Revelation, written in the late first century, names amethyst as the twelfth of the foundation stones of the heavenly Jerusalem. By the end of the fourth century, Epiphanius, Bishop of Salamis, was writing about it in On the Twelve Stones, his study of the gems in the high priest's breastplate.

Amethyst is believed to have been the third stone in the third row of the high priest's breastplate. This religious garment was worn by the Jewish high priest during biblical times.

Amethyst's supposed protection against drunkenness may be the reason why it became popular with the church. In the Middle Ages, it was believed to encourage celibacy and symbolise piety.

More recently, a large amethyst crystal can be seen in the Sovereign's Sceptre with Cross, part of the British Crown Jewels. The stone is mounted below a diamond-encrusted cross with an emerald in the centre. King Charles III held the sceptre in his right hand during his coronation.

Amethyst - The Greek Myth

Countless articles discussing the origins of the name 'Amethyst' cite a myth from Greek mythology. Some now correctly state that it was written by a French poet in the 16th century, but it's rarely repeated as it was written.

We translated the poem from the first edition of L'Amethyste, ou les Amours de Bacchus et d'Amethyste, printed in Paris in 1576. Our article Amethyst and Bacchus: The Original Story by Rémy Belleau retells the poem as it was written.

Article Pictures

The amethyst geode at the top of this article was once part of our collection.

Photo 2: Courtesy of Stan Celestian.

The amethyst ring is featured in the Smithsonian Magazine. The image links to the full article.

Both geodes are on display in the Smithsonian Museum of Natural History, Washington, D.C. Photo: Stone Mania

Photo 5: Courtesy of Ron Wolf.

Photos are clickable and link to the original image on Flickr. You may only be able to view them if you join. Joining Flickr is free, with no additional charges.

Pop-up photos
The snow quartz tumbled stones are from our collection.

The high priest's breastplate is from another article in our blog.