Topaz is a very popular gemstone due to the variety of colors it is available in, its relative durability, and its affordability compared with stones such as ruby, emerald, or sapphire. Let’s take a look at what you should consider when buying a topaz gemstone to add to your jewelry collection.
Topaz Basics
Topaz is a mineral that is colorless in its pure form. However, this gemstone often contains impurities that color it in a variety of tones.
Round blue topaz
You can find topaz in orange, yellow, pink, gray, brown, blue, and green colors.
Rated 8 out of 10 on the Mohs scale of hardness, topaz is a relatively hard mineral, but it can be scratched or even broken by metals and stones that are harder.
Evaluating Topaz: The Importance of Color
Perhaps the most important characteristic of topaz is its color, which to a large extent determines the stone’s value.
Generally, the more intense the tone of a topaz gemstone, the more valuable it is.
Pink and blue varieties of topaz are rare to find, and such stones are quite expensive if their color is natural.
Usually, however, topaz colored blue or pink has been treated with heat or irradiation to achieve such a color.
Yellow is a more commonly seen hue in natural topaz stones, and this color is not as expensive.
When evaluating the color of topaz, don’t forget to look at the stone in different lighting conditions. Depending on whether topaz is exposed to artificial or natural light, the stone’s hue may look more or less saturated.
Gemstones in most jewelry stores are lit in a way that maximizes color, and that’s why you should also examine the stone you are about to buy in daylight.
Topaz and Its Clarity
In general, topaz gemstones with fewer internal flaws are more valuable than stones with more inclusions. To examine a gemstone’s clarity, look at the stone with the naked eye in a well-lit setting – the cleaner the gem looks, the better its clarity.
Keep in mind, however, that since different hues of topaz are caused by different kinds of impurities, some colors of this gemstone are naturally less clear than others.
For example, some varieties of pink topaz tend to look less clean due to the very impurities that cause the stone to be colored.
Evaluating the Cut of Topaz
Since hue is one of the primary characteristics on which topaz is evaluated, this gemstone is usually cut to maximize its color. That’s why the evaluation of this stone’s cut comes down to assessing how well it brings out the gem’s hue.
This is also what you should be looking at when comparing different topaz stones.
In addition, don’t forget to consider how shallow a topaz is cut if you are going to mount it in a setting. For example, stones that are cut too deep leave less of the stone visible when it is set.
So, if you are faced with the choice between two stones of similar weight and color, go for the one whose cut will ensure that more of the gem’s surface will be visible when mounted.
Treated Topaz
A lot of the topaz available today has been treated to improve its color. Very often, colorless varieties of this stone are heated to change their color to blue or another hue.
In addition to heat, irradiation is another method used for color enhancement. The reason color treatment is used so often is that it is rare to find natural topaz with a deep, saturated color, and such stones are too expensive for most people.
Always ask whether the topaz gemstone you are considering has been treated.
It is not easy to tell whether a stone’s color has been enhanced just by looking at it, but the price can give you some clue. Topaz whose color has been artificially enhanced tends to be much cheaper than a similar, naturally colored stone.
Color enhancements of topaz are usually permanent, but you should be careful not to expose a treated gemstone to high temperatures. Heat can sometimes affect the color of gemstones that have undergone enhancements. And some varieties of artificially colored yellow and pink topaz can partially lose their color if left under direct sunlight for a long time.
Topaz Imitations
Very often, varieties of quartz are sold as topaz imitations. When heated, quartz can change color, and this is how fake topaz stones in green, yellow, and other colors are produced.
It is not unlikely to see treated citrine or amethyst (which are both varieties of quartz) sold as topaz.
Sometimes, vendors sell topaz imitations under such names as Brazilian Topaz, Gold Topaz, Bohemian Topaz, and other similar brands.
Be wary of stones branded in such a way, and require a document proving that the gemstone is genuine topaz.
