Topaz is known for being available in a rich rainbow of colours – but orange is the colour most widely known to represent topaz as November's birthstone.
It is often confused with citrine and smoky quartz, but is actually of a completely unrelated species to quartz.
Pure topaz is colourless and transparent, but the stone is normally tinted by its impurities and comes in anything from wine red, to yellow, to blue-brown. It also ranges from transparent to almost completely opaque. The most prized colour is imperial topaz, named after the Russian Czars of the 1800s, which comes in a vibrant orange-pink colour.
Measuring at 8 on the Moh's scale, topaz is a good, durable choice for jewelry.
Topaz is found in the mountains of Russia and Afghanistan, as well as Sri Lanka, Brazil, Mexico, Australia, the United States and several European countries. It is known to have been found as flawless crystals the size of boulders, and some of the larger finds weighing hundreds of pounds can be seen in museum collections.
The name topaz comes from the ancient name of St John's Island in the Red Sea, which was notoriously difficult to find and from which a yellow stone was mined.
The history of topaz is somewhat clouded, because in the Middle Ages the word was used to refer to just about any yellow gemstone. It is also mentioned in the Bible, but the reference could very well relate to chrysoberyl or peridot.
In the 1700s a 1,680 carat stone was found in Brazil, believed to be the largest diamond ever found at that time. However, it was later revealed to be a colourless topaz.
Topaz became well-known in the 19th century after imperial topaz was named to honour the Russian czar. At the time, the Ural mountains in Russia were the gemstone's largest source, and it became restricted for use only by the royal family. Russia aside, topaz was often gifted to those in high standing because it was thought to provide the wearer with wisdom and knowledge.
The market value of topaz varies greatly, from $8 to $749 per carat.
Red, pink and orange topaz is considered the most valuable, followed by yellow. Blue topaz is normally less valuable.
Clarity is one of the most important factors in valuing topaz, and a 10-point scale exists in order to determine a stone's worth.
Topaz is often heat-treated to enhance its colour, and much of the pink topaz in the gemstone trade is heat-treated from yellow or brown-coloured stones.
Radiation treatment is also used fairly often to give blue topaz its colour.
Topaz is another versatile stone that's well-suited to a range of jewelry, from rings, to earrings to necklaces.
Blue, orange and pink topaz are the most frequently used in jewelry, but colourless topaz is becoming increasingly popular as an affordable diamond lookalike.