Many consumers know topaz simply as an inexpensive blue gem, but you might be surprised to learn its blue colour is rarely ever natural – it’s almost always a colourless topaz that’s been treated to give it a blue colour. The Gemological Institute of America unravels the mystery of topaz.
Topaz has many colours to offer the community of gem lovers, including pinks and purples that rival the finest fancy sapphires. In fact, topaz actually has an exceptionally wide colour range that includes various tones and saturations of blue, green, yellow, orange, red, pink, purple, and brown.
Most authorities agree that the name topaz comes from Topazios, the old Greek name for a small island in the Red Sea, now called Zabargad. The island never produced topaz, but it was once a source of peridot, which was confused with topaz before the development of modern mineralogy. Some scholars trace the origin back to Sanskrit and the word topas or tapaz, meaning “fire.”
The ancient Greeks believed topaz gave them strength. Renaissance Europeans (1300s to 1600s) believed topaz could break magic spells and dispel anger. For centuries, many people in India have thought topaz worn above the heart assured long life, beauty and intelligence.
The name for imperial topaz originated in 19th century Russia. At the time, the Ural Mountains were topaz’s leading source, and the pink gemstone mined there was named to honour the Russian czar. Ownership of the gem was restricted to the royal family.
Journey of the Stone
Today, most fine-quality imperial topaz crystals are mined in the Ouro Prêto area of Minas Gerais, Brazil. But even at the Capão mine, known as a source of fine-quality imperial topaz, only 1-2% of the rough is of imperial- colour and suitable for faceted gems. The most common colours from the Capão mine are intense orange-yellow to orange, but the mine also yields some brown crystals.
Highly prized red topaz is also mined primarily in Ouro Prêto. Miners find various blends of red and purple or red and orange. In many of the mines at Ouro Prêto, naturally pink, red, and violet crystals are found along with the imperial topaz.
Because the majority of the world’s high-quality topaz comes from Brazil, events in Brazilian mines and cutting centres strongly influence the supply and price of topaz on the international market.
An area in Pakistan – Ghundao Hill, near the town of Katlang –also supplies gem-quality, naturally pink to red topaz. Like all fine- quality topaz, pink topaz from Pakistan takes an excellent polish and displays a lively lustre. The most-prized pink from Pakistan is faintly violet. Some dealers describe the colour as “cyclamen pink” because it looks like beautiful violet-pink flowers.
Brazil and Sri Lanka are the most significant sources of treatable colourless topaz, while Australia, Madagascar, Mexico, Myanmar, Namibia, Nigeria and the US are minor sources. Most topaz mined in Brazil is cut in Brazil. Other important cutting centres are in Germany, Thailand and China.
Different topaz colours follow different marketing routes. Most consumers in eastern Asia prefer shades of pink and red. The US is a good market for all colours, but prefers blue. Light yellows are popular in Europe. The most selective markets for imperial topaz are Germany and Japan. Dealers in those countries pay higher prices for premium-quality gems than anyone else in the world.
Red is one of the most sought-after topaz colours and represents less than 0.5% of facet-grade material found. Medium reddish orange to orange-red topaz, which the trade calls imperial topaz, is highly prized, very rare and one of the gem’s most expensive colours. Many dealers insist that a stone must show a reddish pleochroic colour to be called imperial topaz. The reddish pleochroic colour often appears at the ends of fashioned gems – like pears and ovals – that have an otherwise yellow-to-orange body colour.
Some say that pink topaz, often called rose topaz, resembles a pink diamond or a bright pink sapphire. Pink topaz has certain advantages over these two gems. It’s much less expensive than pink diamond, and it’s often available in larger sizes than either diamond or sapphire.
Dealers often use the trade term “sherry topaz” for yellowish brown or brownish yellow to orange topaz. The term comes from the colour of sherry wine. Stones in that colour range are also sometimes called precious topaz to help distinguish them from less expensive citrine and smoky quartz, both of which look similar to and are frequently misrepresented as topaz.
Golden or yellow topaz lacks the prized red overtones of imperial topaz. It’s also much more abundant and therefore less valuable. Although brown topaz is also less valuable, it has been used in striking pieces of jewellery and ornamental art.
In nature, topaz is most commonly colourless, and naturally strong blue gems are extremely rare. In the marketplace, however, strong blue shades are plentiful because colourless topaz is treated with a combination of radiation and heat. Treatments have brought blue topaz to a broad market since the 1970s. Treated blue topaz sold for much more per carat when it was first introduced to the market, but oversupply led to huge drops in wholesale prices.
A fashioned topaz that displays a combination of two colours is called bicolour topaz.
Fashioned topaz gems are often free of visible inclusions or flaws.
Because topaz crystals are usually elongated or columnar they’re often cut as long oval or pear shapes to improve yield. If the rough is strongly coloured, the cutter often chooses the emerald cut to maximise colour and retains the most weight.
Topaz is cut in a wide variety of shapes and cutting styles such as ovals, pears, rounds, emerald cuts, cushion cuts, triangle cuts and marquise shapes, as well as designer-inspired fantasy shapes.
Cutting styles are also well represented. Brilliant cuts with triangular and kite-shaped facets, step cuts with concentric rows of parallel facets, and mixed cuts usually consisting of brilliant-cut crowns and step-cut pavilions are all common. Designer cuts fashioned by hand and machines are popular as well.
Because there is an abundant supply of treated blue topaz, it’s often cut into calibrated sizes for mass market and multi-stone jewellery.
Standard topaz cuts for the jewellery industry include a wide range of shapes and sizes. The gem is inexpensive in smaller sizes, but prices rise for gems above 10×8 mm.
Care and Cleaning Guide
Topaz, which rates eight on the Mohs scale of mineral hardness, requires special care during cutting, polishing and mounting. Because it is not very tough, a hard blow might split it, and extreme pressure or sharp temperature changes might cause it to break. Jewellers prefer to set valuable topaz gems in protective mountings or use it in pieces that aren’t exposed to too much wear, like pendants and pins.
The gem’s colour is generally stable to light, but prolonged exposure to heat or sunlight might cause fading in yellow-to-brown, reddish brown, or dark brown topaz. Topaz is affected only very slightly by chemicals.
It’s important to avoid steam or ultrasound when cleaning topaz. Warm, soapy water works best.