In the latter case, the stones must be allowed to cool down to safe levels of radioactivity before being sold. ‘windex’) ” and “London” blues are produced by high-energy electrons (cyclotron) or nuclear radiation. The first, a “sky” blue, is produced by gamma rays (cobalt 60). While the brown color is generally unstable, fading with prolonged exposure to sunlight, the blue color is generally stable under normal wearing conditions. The stone is then heat treated, which turns it blue. For this treatment, colorless topaz is irradiated, turning it brown. Most common is the combination irradiation/heat treatment that produces blue topaz. EnhancementsĪs previously mentioned, several varieties of topaz are typically enhanced. The premier source is near Ouro Prêto in Brazil’s Minas Gerais state.
![topaz clean 3 collections topaz clean 3 collections](https://icdjewelry.com/wp-content/uploads/2020/05/bluetopaz3.jpg)
Gem topaz has been found at a number of localities around the world, including Brazil, Nigeria, Sri Lanka, Russia, Burma, Pakistan, USA and Mexico. However, cut stones of the prized “imperial” colors (orange, pink and red) are more rare. Indeed, faceted stones of tens of thousands of carats have been produced from some monster crystals. Topaz sometimes occurs in enormous sizes, where clean gems of even 1000 cts. The most valuable topaz is a rich pink or red color, and can reach $3500/ct. ‘imperial’ topaz) in rich orange colors fetches prices in excess of $1000/ct. and greater, and sells for less than $8/ct. While natural blue topazes are known, the huge production of treated blue topaz has essentially dropped the price of the natural blue down to that of the treated stone.Ĭolorless topaz, from which blue topaz is produced (via irradiation and heat), is available in sizes up to 100 cts. Blue topaz, the most common variety seen in jewelry today, has been produced in such quantities that today it is generally available for $25/ct. Still, a few generalizations can be made.
![topaz clean 3 collections topaz clean 3 collections](https://4.bp.blogspot.com/-wVYKEfMp7GE/VCrehrN9l9I/AAAAAAAACCU/rozbyzIJ29g/s1600/j55y.png)
The prices of topaz are, like any gem, dependent on quality. Fine pink topaz also comes from the Katlang area of Pakistan. Today, the gem trade generally uses the term for pink, orange and red topaz, which comes mainly from Ouro Prêto, Brazil. According to some sources, pink topaz from those mines was restricted to the family of the Czar. The name “imperial topaz” is said to have originated in the 19th century in Russia, where the Ural Mountain mines were an important source. John’s Island), where peridot has been found.įor the general public, topaz means a yellow gem, and much citrine and smoky quartz has been sold as “golden topaz” and “smoky topaz.” The terms “imperial” and “precious” topaz are often used to distinguish between true topaz and the quartz look-alikes. Some say it comes from the Sanskrit word meaning “fire.” Others link it to the Red Sea Island of Topazios (Zabargad or St. There is some uncertainty regarding the name. Topaz is the name for the mineral species that is number 8 on Mohs’ scale of hardness.