Topaz Grading

Chances are that if you're into blue gemstones, the London Blue Topaz is one of your favorites. After all, they're a lovely steel blue that compliments many skin tones. However, not all London Blue Topaz is created equal. Differences in color and clarity, in particular, detract from its value. This quick guide will show you what to look for in London Blue Topaz jewelry.

London Blue Topaz Meaning

Because London Blue Topaz is nonexistent in nature, its traditional meaning is derived from two sources: Sky Blue Topaz (the only “natural” blue and rare), and topaz in general. Because of its color, London Blue Topaz is very calming. It helps calm nerves, and heal harsh emotions. According to the Vedas, blue topaz is a meditation aid.

Topaz is one of the birthstones for November, a distinction it shares with citrine. This competition has to do with the fact that many topazes are yellow. However, in recent times blue topaz has been used as an alternative. Blue Topaz is a soothing calm blue that is similar to Aquamarine. However, there is a visual difference in the hue of blue of aquamarine and blue topaz.

Topaz Grading Criteria

Like all gemstones, London Blue Topaz comes in a variety of grades. A bird's eye view will show you that topaz grading (and value) is primarily based on three criteria: color, clarity, and cut. Topaz is an abundant gemstone, so there is no “premium” on stones of higher carat. In other words, a two carat gem costs only twice as much as the one-carat gem of the same quality.

Color

For London Blue Topaz, the color is most important. That's because “London Blue” is a specific shade of blue topaz, and it's fairly narrowly defined. London Blue is a medium or dark grey blue. It isn't what people call “sky” blue, nor is it “Swiss” blue. Sky Blue is the one natural blue color of topaz, and it's very light, almost pastel. Likewise, Swiss Blue is more of a medium blue, but without the grey. Color-wise, it's more like aquamarine. Swiss blue is less popular, and less expensive. The natural “sky” blue is more expensive. What's most important about London Blue, is the grey tone in the blue. Some stones do reflect a slight green tinge, which detracts from the value. Lastly, you want the London blue color to be saturated, without lighter spots or a pale steel grey.

Clarity

One of the side effects of London Blue Topaz treatment is that it reduces the appearance of inclusions. This is true both because of the irradiation (darker color masks inclusions) and later heat treatment that's required to produce the blue color (and removes inclusions). Any treatment performed on the London Blue Topaz is permanent, and enhances the beauty of the gemstone forever. Treatments are done for the vast majority of gemstones that are used to craft jewelry.

Simply defined, inclusions are anything that makes the gemstone look less transparent. They could look like specks, cracks, or feathers, for instance. According to the GIA, faceted London Blue Topaz is usually free of inclusions, but they do exist in rough crystals. Here are some examples.

Crystals

Just what they sound like: smaller mineral crystals that got trapped in the topaz crystal as it grew.

Needles

This is a type of crystal, but it is long and thin. So named because it looks like a needle.

Cleavage Breaks

Like diamonds, topaz breaks easily along its “grain.” When this happens in part, you can see a cleavage break without the crystal falling apart.

Feathers

Basically, these are stress cracks in the crystal which look like feathers. Other inclusions can happen in topaz, but they're less common.

Cut

Unlike diamonds and sapphires, the cut of a London Blue Topaz doesn't make a lot of difference except in one area: if the facets are poorly crafted, or the gem isn't polished to a brilliant shine, it's going to be less expensive. Cabochons require less labor to produce, and might be a little cheaper than faceted gems. However, if the cut is well executed, the actual cutting technique or shape has little impact. Here are some common cuts.

Step Cuts

These are cuts where the facets are few, and they are placed along parallel lines. The most famous and popular London Blue Topaz cut is the emerald. A rectangular stone, emerald cuts are often chosen for a London Blue Topaz engagement ring. Other step cuts include the asscher and baguette.

Brilliant Cuts

Intended to bring out the most brilliance, these cuts are generally kite or triangle shaped. Brilliant faceting allows for curved surfaces, unlike step cuts. As a round stone, round brilliants are the most popular choice in London Blue Topaz rose gold ring. Together, the pink and blue produce a lovely contrast. Oval, marquise, pear and heart shaped stones are also made with brilliant cuts.

Cabochon

For a London Blue Topaz with lower clarity ratings, the cabochon cutting style is ideal. These are usually round or oval shaped, with a domed top and high polish. Essentially, the idea is to showcase the color of the gemstone, while making any inclusions part of the work of art. Used for London Blue Topaz ring sterling silver, the cabochon is a great low-cost way to get some bling.

London Blue Topaz Grades

Finally, what grading system is used for London Blue Topaz? Unfortunately, there isn't an “official” scale, but most scales go from AAAA down to AA or even B. Keep in mind that the “ideal” London Blue Topaz has a deep blue-grey color, inclusions that are hard to see under magnification (if any) and are cut competently.

AAAA

At the top, a AAAA topaz is one that has ideal specifications, but hasn't been treated. In other words, this grade doesn't exist in London Blue. Instead it describes Imperial and other natural colors.

AAA

AAA is next: premium grade of topaz, making all the ideal specifications. However, in this case treatment is allowed. The finest London Blue Topaz fits in the AAA grade. With Clarity uses only AAA graded London Blue Topaz.

AA

Next is AA. For these stones, the color might be less intense, or there might be inclusions which are easy to see under magnification. Grades AAAA through AA are often faceted.

B

One more grade, B, is not. These are the stones chosen for cabochons, because they aren't eye clean. Since London Blue Topaz is plentiful, there's no reason to facet low grade material.

At With Clarity, we only make AAA grade London Blue Topaz jewelry. If you have any questions, give us a call. Contact us by phone at 1(844)-234-6463 or email at service@withclarity.com. Our Live Chat is available during business hours Monday - Friday 10AM - 6PM ET.