What is topaz?
Topaz is a gemstone known for its wide variety of colours. Naturally colourless, yellow, brownish, pink or sometimes blue, it can also display much rarer orange, red or purple hues. With a hardness of 8 on the Mohs scale, it is highly scratch-resistant, but its crystalline structure requires certain precautions against impact.
Where does topaz come from?
Topaz is found in several regions around the world. Brazil is one of its most important sources, and the Ouro Preto region is particularly renowned for Imperial Topaz. Pakistan is notably known for its pink topazes, while other deposits are found in Nigeria, Madagascar, Sri Lanka, Namibia, Mexico, and the United States. This diversity of origins contributes to the wide range of colors and sizes in which natural topaz is offered in jewelry.
What are the different colors of topaz?
- Sky Blue topaz displays a light, soft, and bright blue. It is the palest shade among the main commercial designations for blue topaz.
- Swiss Blue topaz is distinguished by a vivid, bright, and much more saturated blue.
- London Blue topaz exhibits a deep and darker blue, sometimes slightly greenish or grayish. It is generally the darkest of the three major commercial shades of blue topaz.
- Imperial topaz is generally in a palette ranging from orange to reddish-orange, sometimes with pinkish hues. Rare and sought after, it is one of the most precious varieties of topaz. However, "imperial" remains a commercial term without a universal color standard.
- Pink, red, or yellow topaz also exists naturally. Red tones and some intense pinks are particularly rare.
The terms Sky Blue, Swiss Blue, and London Blue describe commercial shades rather than official gemological grades.
How to assess the quality of a topaz?
As with other colored stones, several factors must be considered together.
- Color: This is one of the most important criteria. Rarity and value vary considerably depending on the shade. Red, pink, and imperial topazes are much rarer than treated blue topazes, which are widely available on the market.
- Clarity: Faceted topazes, particularly the blue and colorless varieties, often exhibit very few inclusions visible to the naked eye.
- Cut: Topaz can be shaped into many forms, including oval, pear, round, cushion, marquise, and emerald cut. The quality of the cut directly influences its brilliance and how its color is highlighted.
- Stone Weight: Topaz can form large crystals, allowing for generously sized cut stones. However, the relationship between size and value varies greatly depending on the color and rarity of the variety.
Is topaz suitable for an engagement ring?
Topaz offers good scratch resistance. However, it has perfect cleavage, which means that a significant impact in the wrong direction can cause a crack or even break the stone. Therefore, a topaz can be chosen for an engagement ring, provided that the lifestyle of the wearer is taken into account. A prong setting leaves the stone more exposed to impacts and therefore requires more daily precautions.
Our jewellers' opinion
What we love about topaz is that it doesn't lack personality. A London Blue brings depth, and a Swiss Blue immediately catches the light. For a topaz engagement ring, we simply want to remind you that it's beautiful, yes, but not invincible. Its hardness is interesting, but its cleavage requires a well-designed setting and a bit of everyday gentleness. After all, even stones with character like to be taken care of.
Frequently Asked Questions about Topaz
Topaz can be naturally blue, but intense blue colors are very rare in nature. The majority of blue topaz offered today is obtained from colorless topaz subjected to irradiation and then heat treatment. These processes make it possible to obtain Sky Blue, Swiss Blue, and London Blue shades.
Swiss Blue is generally a vibrant and bright blue, while London Blue is distinguished by a deeper, darker, and more saturated color. Sky Blue, for its part, offers the palest blue of the three. These names are commercial color designations.
Lukewarm water and a mild soap are recommended. It is best to avoid steam and ultrasonic cleaning, which can expose the stone to temperature changes or vibrations that could damage it.