All about Topaz

One of the hardest gemstones, and occuring in a wide variety of attractive colours, Topaz has been prized throughout the centuries for its decorative properties. Although the most common variety used in jewellery today is blue topaz, this has only come into widespread use in the last century, with the advent of gamma irradiation, as naturally occuring blue topaz is very rare.

What is Topaz?Back to top

Originally the Greek word topazion was used to refer to any yellow-brown gemstone, after an island in the Red Sea where they were commonly found. Nowadays the mineral we know as topaz is a form of aluminium fluoro -silicate. In pure form it is colourless but naturally occuring impurities usually give it at least a hint of colour.

The colour of Topaz varies from deep salmon pink, to honey yellow, orange to sky blue. Topaz is widely used for jewellery as it is easy to make into faceted gemstones. Sharp blows along the side of a topaz crystal will cleave the stone in a perfect line, allowing all sorts of fancy cuts to maximise its sparkle and fire.

What makes a good Topaz?Back to top

As with any gemstone, size, clarity and colour are all important in deciding the value of a topaz. A gemstone quality topaz should be perfectly clear, without visible inclusions and of a single colour. The most valued colours are pale pink, blue or honey-yellow and this is known as "imperial topaz" (after the Tzars who monopolised this gemstone when it was first discovered in Russia). Most of the blue topaz sold today has had its colour enhanced by gamma irradiation - colourless, pale blue or pale yellow topaz stones can be turned a rich sky blue by bombarding it with gamma rays (the gemstone is not radioactive after this process).

Sometimes other gemstones can be passed off as topaz - the less valuable citrine is sometimes sold as "Brazilian" or "Citrine" topaz, as are various types of yellow-brown sapphires. It can be very difficult to tell them apart, but topaz is denser and has a higher refractive index, so a good topaz will be heavier and have more fire than the equivalent citrine. Accepted names that are often used for topaz include "Precious topaz", "Imperial Topaz", and various terms describing the colour such as "London Blue" (deep blue), "Paraiba" (blue-green), "Sherry" (orange-brown) or "pyncite" (pale yellow). Occasionally blue or pink topazes are themselves passed off as valuable sapphires or rubies.

How to care for TopazBack to top

Topaz is a very hard gemstone, so does not scratch easily. However, the very property that makes it valued for jewellery - its easy, perfect cleavage - means that it requires careful handling, as a sudden blow can make it split or develop internal cracks. It can easily be cleaned with soap or a little detergent and a soft toothbrush and survives most chemical jewellery polishes well. Care should be taken when using a ultrasonic jewellery cleaner, as the gemstone should be protected from sudden shocks.

Famous TopazesBack to top

Some of the largest gemstones in the world are topazes. The largest cut topaz, known as the "El-Dorado Topaz" is a perfect emerald cut honey-yellow topaz weighing 31,000 carats (approx 6.2kg), owned by the Pro gramma Royal Collections group in Spain. Other notable topazes include the 21,327 carat "Brazilian Princess" and the 1640 carat colourless "Braganza diamond" set in the Portugese Royal Crown.

Myths and legendsBack to top

Like many gemstones, Topaz was thought to have healing properties. Due to its association with the Sun, it was said to have the power to dispel enchantments or protect from the "evil eye" and to increase physical strength. In the Bible, topaz is the 9th foundation of the New Jerusalem (Revelation21:20).

Place of originBack to top

The largest topaz crystals are found in Brazil and are typically a yellow-brown colour, although the mines at Minas Gerais also yield honey-yellow, pink, red and blue topaxes as well. Imperial topaz originally comes from Russia and the Urals are still an important source of blue, pink and colourless stones. Other deposits include Queensland in Australia, Colorado, California and other mountainous areas in the US as well as Nigeria and Sri Lanka. Small amounts of topaz can be found in Northern Ireland, Scotland and Cornwall (in the old tin mines), but is rarely of gemstone quality.

Technical informationBack to top