Topaz
Topaz is a gemstone found in a variety of colours, probably the best known of which are blue and golden orange. It's often set in gold or silver and popular topaz jewelry you can buy includes earrings, necklaces and bracelets. Amongst its uses topaz features as a birthstone: yellow topaz is one of the birthstones for November, blue the stone for December.
What Is Topaz?
Topaz is a form of fluorine aluminium silicate. The pure stone is essentially colourless however it can acquire a variety of hues through the presence of impurities. The colour can also be enhanced or changed by heat treatment, a process discovered in the 18th century.Most of the blue topaz you buy today has probably been heat treated to improve and deepen the colour. Natural yellow topaz can be changed to a pink colour by treatment and the majority of the pink topaz available to buy today has been produced this way.
Some forms of the more common citrine resemble yellow topaz and some dealers have been known to try to sell these as true topaz. Always buy from a reputable dealer and get expert assistance if in any doubt.
Topaz had a variety of uses in legend. It seemed to be associated with eyesight; on the one hand it was said to be an ingredient of an invisibility spell, on the other wearing a topaz charm was said to help improve eyesight.
Varieties
Topaz occurs naturally in many forms. In addition modern laboratory treatments can produce numerous other colour variations. Two of the best known are the Imperial and Mystic varieties.
Imperial Topaz
The golden orange variety of topaz is rare and one of the most valuable varieties. The exact hue can vary from browny orange through to almost pink.The name "Imperial" comes from the 19th century when it was mined in the Ural mountains and used in the jewelry of the Russian royal family. Imperial topaz is also sometimes called "Precious" topaz for obvious reasons, however the range of hues in which the stone is found means that not everyone agrees on the exact definition of these terms. As always, make sure you know what you're buying and don't by the label alone.
Mystic Topaz
Mystic or Mystic Fire Topaz is a strange and enchanting gem that's been introduced relatively recently. It doesn't occur naturally but is created by treating colourless ("white") topaz.The original stone is treated with a special ultra-thin titanium coating. This coating creates interference patterns that give the stone it a multi-coloured "rainbow" effect. This can create a stuning appearance, especially when set and worn as a solitaire ring or pendant. The exact effect will depend on the nature and cut of the original stone and the final visual appearance combined with personal taste will affect its value and price.
As well as being called mystical this variety is sometimes referred to by the French description topaze mystique.