Distinguishing Features
Topaz is one of the US birthstones for November.
Irradiating colourless topaz with electrons at an energy of 10 million electron volts creates a sky-blue colour.
Topaz comes in some of the gem world’s most giant crystals: the largest is in kilos, not carats. A transparent topaz crystal discovered in Minas Gerais, Brazil, weighs an astounding 596 pounds (271 Kilos)
The Most Desirable Picks
Colour:
In nature, topaz is most commonly colourless, naturally blue gems are extremely rare. However, strong blue shades are plentiful in the marketplace, blue topaz is known to many consumers as an inexpensive gem, this colour is almost always caused by treatment.
Topaz has a wide range of colours that includes various tones and saturations of red, pink, purple, yellow, orange, brown, blue and green, as well as colourless.
Precious topaz (or Sherry Topaz) is a grade term for orange to yellow and brown topaz.
Red is one of the most thought-after topaz colours and represents less than 0.5% of facet-grade material found. Red and pink topaz varieties, including imperial topaz, are highly prized and rare.
Imperial topaz is a widely used trade term for gem-quality topaz of medium reddish-orange to orange-red colour. Many dealers insist that a stone must show a reddish pleochroic colour to be called imperial topaz.
Clarity:
Faceted blue topaz is almost always free of eye-visible inclusions. Other more rare colours like imperial and pink may show inclusions more often and still be valuable due to the colour’s rarity.
Carat:
Topaz often forms as large crystals. These can yield sizable cut gems. Standard topaz cuts for the jewellery industry include a wide range of shapes, sizes and weights. Blue topaz rises very little in per carat price as the size increases. Imperial topaz on the other hand rises in per carat price dramatically as size increases.
Cut:
Topaz is cut in a wide variety of shapes and cutting styles. Production includes all the standard gem shapes such as ovals, pears, rounds, emerald cuts, cushion cuts, triangle cuts, and marquise shapes, as well as designer-inspired fantasy shapes.
Topaz crystals are usually columnar, and shapes such as oval or pear improve yield. If the rough is strongly coloured, the cutter often chooses the emerald cut because this cutting style maximises colour and retains the most weight.
Origins
The Ouro Preto area of Brazil is the world’s major commercial source of imperial and red topaz, it is where most fine-quality imperial topaz crystals are mined. But the yield of facet grade imperial rough is low at many Ouro Preto mines, naturally pink, red, and violet crystals are found along with the imperial topaz.
Ghundao Hill near the town of Katlang in Pakistan supplies gem quality, naturally pink to red topaz. The most prized pink from Pakistan is faintly violet, some dealers call the colour ‘cyclamen pink’.
Brazil and Sri Lanka are the most significant sources of treatable colourless topaz, while Australia, Madagascar, Mexico, Myanmar, Namibia, Nigeria and the U.S. are minor sources.
Significant Pieces
Swedish Pink Topaz Demi-Parure
The Swedish Royal Family possesses this Russian pink topaz demi-parure, which was given to Maria Pavlovna by her father Tsar Paul I on the occasion of her wedding to the Hereditary Grand Duke of Saxe-Weimar-Eisenach in 1804. It passed to her daughter Empress Augusta of Germany, and then to Augusta’s daughter, Louise, Grand Duchess of Baden. In 1923, it was passed to Louise’s daughter, Viktoria of Baden (Queen Victoria of Sweden). It has been part of the Bernadotte collection ever since. Queen Silvia wore the demi-parure to Crown Princess Victoria’s wedding in 2010.
The Demi-Parure consists of a heavy necklace with three pendants, a small round brooch, and a larger brooch with three pendants, which can be detached to be worn as earrings, all of which are set with magnificent, high-quality, Pink, Russian Topazes.
Formation
While some topaz crystals grow in metamorphic rocks or hydrothermal veins, most form in cavities in igneous rock like granite and pegmatite. The primary sources of gem-quality topaz are pegmatites, where miners sometimes find huge crystals in cavities and pockets.
Stability
Care and Cleaning
Because of its cleavage, topaz requires special care in cutting, polishing, mounting and wear.
Avoid using hot water or scrubbing your jewellery with harsh or abrasive chemicals like chlorine or bleach, and avoid using ammonia-based cleaners.