There is limited consensus on where the name Topaz originated. The most plausible is that it is named after an island in the Red Sea formerly names Topazos, although today know as Zebirget. The complication arose from a time when all yellow, brown and even green stones were collectively known as “Topaz”.
Topaz comes in many colours naturally, including clear, brown, yellow, orange, red, pink and blue. The most common colour is yellow with a red tint; the most valuable is pink to reddish. The colouring agents are iron and chromium.
The fine golden-yellow variety, known as Imperial Topaz, is relatively scarce. Topaz colours are rarely vivid, and as such the vast majority of today's commercially available cut stones have been enhanced, including those we sell on our website.
Pure Topaz is colourless and transparent; it is only with the inclusion of impurities (trace elements) in the crystal lattice that colour is imparted to the stone. The common colours are brown, yellow, golden, orange, red, pink and blue. The coloring agents are iron and chromium.
Blue topaz
While natural blue topaz is rare, pale blue, pale yellow and white stones are commonly treated to produce the popular blue colours sold as: Sky Blue, Swiss Blue and London Blue.
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Blue Topaz 10.00mm Round, 4.97 carats |
White Topaz:
This naturally occurring colourless variety of Topaz has enjoyed tremendous interest in the past five years. As a natural, semi precious alternative to Diamond or White Sapphire, this stone is a cost effective alternative in everyday jewellery where a white stone is required.
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White Topaz 10x5mm Marquise, 1.15 carats |
Mystic Topaz:
Displaying a kaleidoscope of iridescent colors, Mystic Topaz (also known as Mystic Fire Topaz), was first launched to the public in 1997. The popularity of Mystic Topaz increased dramatically when it was exhibited at the Tucson Gem Show in 2003.
Mystic Topaz is produced using a metallic vapor deposition coating process. This coating is applied to typically only the top (crown) of a facetted white Topaz. The treatment while hard wearing is only 1 micron or so thick, and can become abraded or even removed following polishing of the stone (when jewellery is cleaned), or from everyday wear and tear that will impart micro scratches to the stone surface, effectively cutting through the coating. The stones iridescent appearance changes depending on the light source and the viewing angle, adding to the fire effect of the treatment.
In addition to the iridescent fire colours, brilliant shade or blue, green and orange among others are also currently being produced and marketed.
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Mystic Topaz 12.00mm Round Concave Cut, 6.97 carats |
Imperial topaz
This the most sought after of all natural Topaz. Its rich golden color is generally not enhanced by any kind of treatment.
Pink topaz
Natural pink Topaz is very rare and costly. The vast majority of pink topazes are heat-treated yellow stones that turn pink. Pink Topaz is also being produced in large quantities using a similar vapour depositing process as Mystic Topaz, this to satisfy the current worldwide demand for pink coloured stones.
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Pink Topaz 12x12 Heart, 7.45 carats |
Topaz is a very hard gemstone (8 on the Moh's scale) with a high refractive index thus making it ideal as an everyday gemstone.
Colour
For totally natural stones the golden-yellow variety, known as Imperial Topaz, yellow with a red tint or the most valuable pink to reddish stones are popular albeit at a price premium due to their scarcity. Without doubt the most popular colour is Blue topaz, followed by Pink and then the Mystic colours (all being enhanced stones)
Lighting
Topaz is a pleochroic stone, exhibiting different colour when viewed along different axis. No discernable difference is seen between natural and artificial light sources for viewing the stone.
Clarity
Topaz is a Type 1 clarity gemstone and as such only eye clean examples should be considered for purchase.
Cut
Topazes are generally cut in the simple step cuts, although any cut can be encompassed. The cutting style for weakly colored stones tends to be the round brilliant cut, which imparts more colour to the stone, or any of the cuts where additional facets have been added to enhance the lustre.
Mineable Deposits
While the 18th century deposits of Saxony are today all but depleted, other major deposits had been found to replace the significant consumption of this gemstone. The largest current deposits are in Brazil (Minas Gerais, Esperito Santo) Other significant deposits are located in Sri Lanka, Myanmar and Russia, with lesser deposits in Afghanistan, Australia, China, Japan, Madagascar, Mexico, Namibia, Nigeria, Pakistan, United States and Zimbabwe. Natural light blue topaz is also found in England (Cornwall), Northern Ireland and Scotland.
Topaz – Common Treatments
The most common treatments for natural rough Topaz (colorless or very lightly tinted), is either neutron irradiation or linear acceleration. which are use to create the Blue Topaz commonly available in most jewellers nationwide. Neutron irradiation followed by stabilisation with heat is use to produce the Swiss Blue Colours (Baby Swiss, Light Swiss, Swiss, Top Swiss) through the strong blue colours (Korean Blue & Maxi Blue) to the dark London Blue Topaz (blue with a green/grey overtone) . The depth of colour in neutron irradiation is a function of the length of time the rough material is exposed to the isotope Cesium 137. As reactor time is expensive so the darker colours are sold at a premium over their light counterparts. The perennially popular Sky Blue Topaz is enhanced using LINAC (linear acceleration) a less expensive enhancement method result in an Aquamarine coloured stone .
In 1997, a new type of enhanced Topaz made its appearance, the surface-enhanced Topaz, with colors described as blue to greenish-blue or emerald green.
The vast majority of pink Topazes are either heat-treated yellow stones that turn pink, or are the result of a metallic vapor deposition coating process.
Displaying a kaleidoscope of iridescent colors, Mystic Topaz (also known as Mystic Fire Topaz), was first launched to the public in 1997. The popularity of Mystic Topaz increased dramatically when it was exhibited at the Tucson Gem Show in 2003. Mystic Topaz is produced using a metallic vapor deposition coating process. This coating is applied to typically only the top (crown) of a facetted white Topaz. The treatment while hard wearing is only 1 micron or so thick and can become abraded or even removed following polishing of the stone (when jewellery is cleaned), or from everyday wear and tear that will impart micro scratches to the stone surface effectively cutting through the coating. The stones iridescent appearance changes depending on the light source and the viewing angle, adding to the fire effect of the treatment.
Important & Famous Topaz
Topaz is a gemstone who's formation allows for the growth of some very large crystals. In 1967 a Blue Topaz of nearly 100kg (500 000 carats) was discovered in the Ukraine. The Smithsonian Institute in Washington has several large examples on display, including a single facetted stone weighing 22,892.50 carats, making it the largest cut yellow topaz in the world.
Perhaps the most famous Topaz is a giant specimen set in the Portuguese Crown, the "Braganza", which was first thought to be a diamond.
Topaz – The Legend
There are many ancient stories and beliefs that have created an interesting history for Topaz. The Egyptians called Topaz the “Gem of the Sun,” and believed it was colored by the golden glow of their sun god Ra and thus a powerful protector from harm.
Greeks and Romans also associated Golden Topaz with their sun god, Jupiter. They believed the gem increased their strength and could neutralize spells and curses.
Topaz is mentioned in the Bible as being one of the “stones of fire” (Ezekiel 28:13–16) that were given to Moses and set in the breastplate of Aaron (Exodus 28:15–30). Topaz is also one of the twelve gemstones set in the foundations of the city walls of Jerusalem (Revelations 21:19) and associated with the Apostle Matthew.
Bushmen here in Africa used topaz in healing ceremonies and rituals to connect with ancestral spirits.
Topaz is the birthstone for November, and for those born under the star sign of Sagittarius.
Taken from www.touchstonegems.co.za
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