How to assess a Amethyst’s quality and value?

Our gem expert assesses the quality of amethysts very much in the same manner as diamonds. He first studies their clarity, followed by colour and cut.

A high quality amethyst will appear clear of inclusions when examined without a magnifying jeweller’s loupe. It should exhibit a vibrant purple or lilac colour, enhanced by the gem’s cut.

So called “colour zoning” is not desirable in an amethyst that’s been set in jewellery – this is where a single gem appears to have patches of more than one colour within it.

COLOUR

An amethyst’s color can range from very light lilac to red-purple, brown-purple or dark blue-purple. Strongly saturated colour is preferable, but you should avoid very dark tones because they do not let enough light into the stone. A vibrantly coloured, but transparent amethyst will offer the best sparkle.

CARAT

The amethyst occurs abundantly as large, clear crystals, especially in Brazil. Therefore its carat price shows no dramatic rise as the gem gets bigger. It’s the perfect gemstone for large, showstopping jewellery pieces at a very affordable price.

CLARITY

Because amethyst is abundantly available today, there is a general expectation for it to be eye-clean when sold as jewellery. Some redder hued amethyst varieties from Africa may have noticeable imperfections, but the purple type from Brazil is generally very clean.

CUT

Amethyst is a gem that can easily be cut into many different shapes. These include standard cuts, such as rounds, ovals, emerald cuts or pear shapes. Because amethyst is readily available, cutters can afford to discard relatively large amounts of the stone. This has led to the popularity of fancy shapes like hearts and triangles, as well as one-off designer cuts.

Purple amethyst generally needs no treatment. Because of its ample availability, it is usually expected to be natural.

However, some amethysts are subjected to heat treatment to turn them yellow. This heat treated variety is sometimes referred to as citrine, which is in fact a yellow, naturally occurring variety of quartz. A reputable jeweller will always tell you if any treatments have been applied.

Amethyst is relatively tough and therefore suitable for all jewellery types, including large rings. However, you should protect it from scratching, excessive knocks and heat.

Harder gems like diamonds or sapphires can scratch amethyst, so always store your gemstones separately. Your amethyst may also discolour when exposed to harsh light and heat, so never sunbathe with it on and do not steam wash it. To clean it, just soak it in warm, soapy water, scrub with a soft toothbrush and pat dry.

Amethyst has always been the most valued quartz variety. The Queen of Sweden’s tiara, which originally belonged to France’s Empress Josephine, features enormous oval amethysts surrounded by diamonds. Queen Elizabeth II also has a stunning amethyst set called the Kent Demi-Parure.

Abundant Brazilian amethyst mines were discovered in the 19th century. Thanks to this, the gemstone has become very affordable and is no longer exclusive to aristocrats and collectors.

The infamous “Delhi sapphire”, which is in fact a purple amethyst, has a rather mysterious story. Stolen from an Indian temple, it is said to be cursed

A young curator called Peter Tandy found it in the British Natural History Museum’s vaults – along with a letter from its previous owner warning that it brought bad luck. When Tandy ignored the ominous message and took the stone to a science symposium, he was caught in a horrific thunderstorm and fell ill with kidney stones.

But despite the amethyst’s dangerous reputation, today you can see it on display in the Natural History Museum in London.

Amethyst has an enchanting and interesting history. In ancient Greece it was believed to help its wearer think clearly – as well as prevent drunkenness. Tibetan Buddhist monks regard amethyst as a sacred stone, using it for prayer beads.

According to Roman legend, Saint Valentine himself wore a purple amethyst ring with an engraving of Cupid on it. As the holy man travelled around the Roman Empire, people would recognise the image on his ring and ask him to perform marriages. Today we still celebrate St. Valentine’s Day on 14th February – and the amethyst remains the symbolic gem for attracting love.