Topaz, traditionally considered ‘semi-precious’, is a fine gem that can be found in an amazing array of colours including: red, orange, yellow, brown, blue, and colourless. Different colour varieties can have very different values.
The most sought after colours are the reds and orangey-pinks called Imperial topaz. Imperial topaz is significantly more expensive than other colours especially blue topaz.
Where can you find the topaz you need ?
Pierres de Charmes carries a vast selection of fine quality Imperial and blue topaz. Our collection of well-cut stones includes many different shapes and sizes including calibrated stones.
Did not find what you were looking for?
|Perfect and moderately easy in one direction|
|Refractive index||1.619 to 1.627|
3.50 - 3.60
Topaz is anisotropic and shows a moderate dichroism of two tones of the body colour.
Gemmologists can use many instruments to identify topaz. Many topazes are inclusion free, however, certain inclusions when present can be very helpful in identification. These include: incipient cleavage, cavities filled with 2 immiscible liquids, long hollow tubes, and healing fissures.
Rough topaz crystals usually present as elongated orthorhombic prisms. Prism faces are often heavily striated and terminated with cleavage surfaces. Clean crystals are facetted while translucent or heavily included material can be fashioned as cabochons. Some topaz crystals are exceptionally large and these can be used to create impressive sculptures.
Brazil is the primary source for Imperial topaz and other gem quality topaz. Other producing countries include Australia, Japan, Madagascar, Myanmar, Mexico, Pakistan, Russia, Sri Lanka, Zimbabwe, and the United states. Many sources outside Brazil produce mainly commercial grade goods that are treated to become blue.
Is topaz treated ?
Although natural blue topaz exists, most blue topaz on the market is a result of treating colourless topaz with a combination of irradiation and heat. This treatment is stable and poses no risks. Pink topaz is also often the result of treatment; brown or yellow topaz is heated to get various shades of pink.
Colourless topaz is often treated with a chemical coating process that produces a wide variety of colours. This type of treatment is generally applied to the stone’s pavilion and may show an iridescent effect on the surface of the stone. It is easily detected with magnification and should be treated with care, as it is not permanent.
Topaz in Jewellery
Topaz has always been a popular choice with both jewellers and clients. Its hardness, toughness, and stability make it suitable for all types of jewellery and allow it to maintain its beauty over time. Gemstone enthusiasts enjoy the affordability of many topaz varieties especially blue topaz.
Imperial topaz is the birthstone for November and the gemstone for the 23rd wedding anniversary while blue topaz is the birthstone for December and the gemstone for the 4th wedding anniversary.
Value and Quality Criteria
Intense and saturated colours will have more value. Clarity and size are important value criteria for topaz. The quality of the cut will also have an impact on the gem’s overall appearance and value.
The most desirable topaz colours are the reds, orangey reds, and pinkish oranges of Imperial topaz that are caused by small amounts of chromium present in the structure. Less than 0.5% of all gem quality topaz is red.
Modern science has allowed manufacturers to make synthetic versions of many natural gemstones. Synthetic gems have the same physical and optical properties as their natural counterparts. Natural topaz’s abundance and affordability make it one of the few gems not grown in laboratories.
Gem property Chart A [Chart]. (n.d.). In Gemological Institute of America (GIA).
Top-2. In Cours de base en gemmologie Gem-A. London, 2010
Top-1. In Cours de base en gemmologie Gem-A. London, 2010
What is Topaz Gemstone | Topaz Stone – GIA. (n.d.). Retrieved August 12, 2016, from http://www.gia.edu/topaz