The Yellow Topaz
Added over 7 years ago
Who first comes to this world below
In dreary November's fog and snow,
Should prize the topaz amber hue,
Emblem of friends and lovers true
Birthstone for November
Topaz is silicate based (Al2SiO4(F,OH)2) and is one of the hardest minerals found in nature. Single topaz crystals can also reach the incredible size of several hundred kilograms. Pure topaz is colourless and transparent but is usually tinted by chemical impurities. Typical topaz colours are yellow, reddish-orange and brown; more rarely specimens may be white, pale green, blue, gold or pink (the rarest of all colours). Some topaz colours are unstable and can fade away when exposed to sunlight, while colour changes can be induced by heating and irradiating pale stones, most commonly to a beautiful aqua-blue tint. So called "mystic topaz" is colourless material which has been artificially coated to give it a rainbow effect. Topaz is very attractive to the jewellery industry because of its hardness, clarity, fire and range of beautiful colours, and holds it value well because of its relative rarity. Pure topaz, when brilliantly cut, may be mistaken for diamond.
Topaz deposits are found in many parts of the world including the Ural and Ilmen mountains of Russia, in Afghanistan, Sri Lanka, the Czech Republic, Germany, Norway, Pakistan, Italy, Sweden, Japan, Brazil, Mexico and the United States. Blue topaz is the Texas state gemstone, while the deposits of Brazil produce some of the most spectacularly sized and coloured specimens ever found.
The most famous topaz in the world is a colourless stone known as the "Braganza Diamond" set in the Portuguese Crown Jewels. Originally thought to be a diamond, it weighs a whopping1680 carats. The world's largest faceted gemstone is the "El-Dorado Topaz", weighing 31,000 carats (equivalent to 6.2 kg). When first discovered in Brazil in 1984, the rough "El-Dorado" crystal actually weighed 37 kg; a total of 30.8 kg of stone was cut away to reveal a final stone of perfect cut, clarity and golden colour.
Historically, the ancient Greeks believed that topaz had to power to increase strength and to make its wearer invisible while the Romans believed it could improve eyesight. The Egyptians wore it as an amulet to protect them from injury. During the Middle Ages, topazes were worn mostly by royalty and clergy to help cultivate the goodwill of kings, princes and magnates. The stone was thought to have the power to cool boiling water and excessive anger and as medication, ground topaz was added to wine to cure fever, prevent asthma and insomnia, strengthen the mind, increase wisdom and prevent mental disorders.
Citrine, the pale yellow gem belonging to the quartz species is considered an alternative to topaz as the birthstone for November. Named from the French word for lemon, citrine has the advantage of being a very affordable gemstone thanks to its ready availability. In ancient times, citrine was carried as a protection against snake venom and evil thoughts.
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