Blue topaz is the most popular topaz variety and is one of the most coveted gemstones to be ring mounted.
But did you know it ?
The topaz blue color is most often obtained by treatment.
Blue topazes are distinguished by three distinct shades of blue : London blue, Swiss blue and Blue sky, which you can observe comparatively in the following picture.
From left to right, Blue sky topaz, Swiss blue and London blue
Topaz is a very hard fine stone that can take a wide color range naturally or by treatment, ranging from natural imperial topaz to mystic topaz, yellow topaz or even pink topaz.
Natural crystals of topaz ranging from yellow to pink through brown (photo source)
We suggest you take stock of this fine stone so popular in jewelry.
Topaz stone generalities
Topaz is a stone known since antiquity, its name comes from the Greek Topazos. It has been used for millennia as amulet, stone of power and subsequently in jewelry.
Pure topaz is transparent, it's the impurities present in its structure which colors it.
Topaz is a Pleochroic stone, that is, it changes color depending on the angle from which it is viewed, as shown in this video:
Topaz stone is a fluorine-containing aluminum silicate of formula Al2SiO4 (F, OH) 2 and may contain traces of other metals. The result is a very hard mineral, hardness 8 on the Mohs scale.
In comparison, topaz is less hard than rubies, sapphires and diamonds, but harder than emerald, beryl, tourmaline or aquamarine.
Comparative table of the hardness of topaz with other fines stones
The Topaz particular crystalline structure brings it closer to diamonds and makes it fragile to blows. We go back further in our chapter ; topaz maintenance.
The color of the different topaz varieties corresponds to the substitution of aluminum atoms by chromium atoms, iron or cobalt in the crystalline structure.
Natural topazes from Brazil and Russia (photo source)
Topaz stones may show a color change as a result of prolonged exposure to sunlight.
Topaz exploitation and mining
The raw topaz stone is in the form of a generally elongated crystal.
Natural crystal of colored elongated topaz (photo source)
Topaz natural crystals can be particularly big. In 1965, a topaz of about 100 kilograms was discovered in Russia and specimens weighing several kilograms are common.
The brown topaz El Dorado is currently the largest cut crystal in the world with a weight of 31,000 carats. With a weight of 6.2 kg, the gross weight of this stone was 37 kg when it was discovered in 1984 in the state of Minas Gerais in Brazil.
Topaz deposits have been found in many countries : Brazil, Afghanistan, Australia, Myanmar (Burma), China, Germany, France, Japan, Madagascar, Mexico, Namibia, Nigeria, Pakistan, Russia, Zimbabwe, Sri Lanka, Ukraine and USA.
This map recalls the main operating sites in the world:
Topaz exploitation main sites in the world, established by Aurélien Reys, gemologist whose publications are available here.
The notable deposits are those:
- from Brazil that produces the highest quality natural colored stones for jewelry today. Mines of Vermelhão and Xanda in the state of Minas Gerais.
- Pakistan, which produces colored topazes in the districts of Gilgit, Baltistan, Shigar and Katlang.
- from Russia which historically was a big producer of high quality blue topaz. Topazes are extracted from the Ural mountains, including the Blyumovskaya mine.
- from France with the topaz mines of Montmins, Échassières, Ébreuil, Chavence, La Vilate, Chateloube, Razès.
- from the United States with Thomas Tange Mine in Utah, famous for its natural cherry pink topazes.
Topaz stones colors
Topaz is a stone that can present a wide range of colors, which can be transparent, yellow, orange, brown, pink or blue depending on the present impurities or the treatments applied to the stone.
Blue topaz is the best known and the most common of all varieties of topaz.
Natural blue topaz is very rare. Its color is due to imperfections at the atomic level of its crystalline structure.
So most of the blue topazes on the market are actually transparent topazes that have been treated by irradiation and then by heating to give them their blue tint.
This method nevertheless has the advantage of giving a stable color to the stone which won't vary over time.
Orange-red topazes are called imperial topazes. These are the most coveted and also the most expensive topazes.
Their color is due to the presence of chromium atoms in their crystalline structure.
Mystic treated topaz
Mystic topaz is a transparent natural topaz that has undergone a surface treatment giving it its characteristic appearance and different from other types of topaz.
Its appearance is due to a surface deposit, it will tend to disappear over time due to wear and friction.
Yellow and brown topazes
Yellow and brown topazes, too, owe their color to the presence of impurities in their crystalline structure.
Brown topazes with their shallow color are often called through misuse of language ; smoked topaz.
Natural pink topaz without its rock matrix (source GIA)
The natural pink topaz is expensive, its color is due to the presence of chromium atoms in its structure. This topaz color is very popular in Asia.
The low-priced pink topazes found in jewelry are obtained by heat treatment or coating of ordinary topazes.
Of course, the pink topazes obtained by coating will have a wear that will not present heated topazes.
Topaz stones maintenance
Because of its crystalline structure, the care to be given to your topaz is important, because the topaz has a tendency to break on one of its cleavage planes when it receives a blow.
Therefore, the risk is not to damage the stone but to break it completely.
Topaz is also sensitive to heat and strong changes in temperature that can cause it to crack.
When storing your jewelry set with turquoise, be careful not to mix your topaz with other stones because they could scratch them, the topaz is indeed the hardest of all fine stones.
For topaz cleaning, you can use an old toothbrush with soap and lukewarm water.
Avoid water vapor and ultrasound which could damage the stone.
If your stone is coated, avoid abrasive cleanings that could damage the coating. This is particularly the case with mystic topazes.
The price of a topaz is very variable depending on whether one is talking about a treated topaz or a natural colored topaz obtained without treatment.
Prices can vary from a few tens to several hundred dollars per karat.
To have a more precise vision, I invite you to consult this table which indicates you the price in dollars of the topaz karat according to its quality and its color :
Topaz mounted in jewel
Here are some examples of custom made rings in our workshop with topaz stones.
For further :