London Blue Topaz Gemstone Guide

London Blue Topaz Gemstone Guide

An Introduction to London Blue Topaz

London blue topaz is different from other blue topaz gemstones due to its shade of blue. London blue topaz has a very definitive shade of blue that is darker and inky compared to regular topaz. However, it is much lighter than a sapphire gemstone.

What makes this gemstone so valuable and important is the color and the hardness. Blue gemstones of any sort that have decent hardness and good brilliance are hard to come by.

London blue topaz is quite popular compared to other gemstones. It is more valuable because blue topaz is relatively rare. In general, natural topaz that hasn’t been treated is usually colorless. Any variation of topaz that is blue is going to be quite valuable, especially if it is natural. The majority of blue topaz on the market has been treated with radiation to achieve its color.

Blue topaz is the December birthstone. In general, the London blue topaz is the more desirable of the colors available. Blue topaz symbolizes honesty, clarity of feelings, and emotional attachments.

London Blue Topaz Hardness

London blue topaz is rated 8 on the Mohs scale of hardness. This means that it is quite durable, almost as durable as a sapphire. It is a great gemstone to wear on a daily basis. However, blue topaz can get damaged if it gets hit at a specific angle due to its cleavage. Cleavage is comparable to the grains of wood. Wood will split with the grain the same way that crystals will break.

Due to its durability, London blue topaz is commonly used in all kinds of jewelry. Earrings, necklaces, bracelets, and rings. However, on the market, you will find that it is most often used in rings.

London blue topaz has a unique shade of blue that pairs beautifully with silvers, white golds, and diamonds, making it a great engagement ring option. It is also the universal gift for a 4th anniversary.

London Blue Topaz Shapes

London blue topaz is similar to other gemstones in the way it can be cut and shaped into almost anything your heart desires. Cabochons are the oldest form of the cut gems and can be oval, square, rectangular, or round. However, cabochons are often only used to cut eye clean gemstones. They are not often used for rough gemstones with heavy inclusions.

Some of the most common cuts that you will find on a London blue topaz are step cuts, emerald cuts, brilliant cuts, and round cuts. The step cut is one of the most popular cuts used on a London blue topaz because the facets will run parallel to each other. This allows for light to reflect and for the gem to shine as much as possible. The only downside to the step cut is that it is harder to hide inclusions because by design, it is meant to show off the clarity of a gemstone. If you are feeling fancy or eccentric, try an oval, heart, or pear shape cut.

London Blue Topaz Sizes

The largest blue topaz ever found was 9,381 carats. They can range from 0.11 carats to an average of 9.52 carats. You can get them in basically any size or cut you would like. While it is fairly easy to find good quality London blue topaz stones in large dimensions, this greatly depends on your definition of large.

London Blue Topaz Colors

London blue topaz comes in a variety of colours, but the one that is the most well-known is a medium to dark blue that has an inky or steel-like appearance. It can sometimes look a little gray, and in other instances it can have a slight green tone. This also depends on lighting and angles.

You can find London blue topaz in lighter and darker tones. On the market, they are known as sky blue topaz, and Swiss blue topaz. When it comes to the value, the more saturated blues have a higher price tag which is why the London blue topaz is considered the most valuable. If you are looking to buy a London blue topaz, keep the colors in mind when viewing the stones. The blues should be heavily saturated with a greenish or grayish tint.

London Blue Topaz Clarity

When it comes to the clarity of a London blue topaz, they are quite similar to diamonds. Blue topaz has inclusions, but they are eye-clean like diamonds. This means that you won’t be able to see the inclusions just by looking at the stone with the naked eye. According to the GIA, the majority of London blue topaz is free of inclusions, but you will definitely find inclusions in the rough crystals that have yet to undergo any treatments.

The value of London blue topaz can be impacted by the clarity and size. However, the value has more to do with the colors and the intensity of the hues. The highest values will be awarded to the rare pinks and blues, even if they have some inclusions.

London Blue Topaz Sourcing

Unlike other gemstones, London blue topaz is not found in very many spots around the world. Historically, the majority is mined and found in Brazil. However, a few natural blue topaz gemstones were recently discovered in the United States. Due to this discovery, blue topaz is now the state gem of Texas. Blue topaz are still quite rare and they are not found abundantly in either country.

London Blue Topaz Treatments

Blue topaz is rare to find existing in nature. That is why the majority of blue topaz, especially London blue topaz, is created through heat treatment or irradiation.

The first step in identifying if the blue topaz you have is 100% natural is to analyze the color and the price. If the price is the same as a London blue topaz, then it is not 100% natural. As we mentioned, natural blue topaz is incredibly rare and will be priced accordingly. Natural blue topaz is very light. London blue topaz, on the other hand, is darker. The London blue topaz color is obtained once a colorless topaz has been irradiated, which creates that darker hue not found in nature.

London Blue Topaz Buying Guide

When buying a London blue topaz piece of jewelry, there are a few things to keep in mind. For starters, consider your budget. London blue topaz is not a rare or naturally occurring gemstone, so make sure that the price point is appropriate for the gemstone and for your personal budget. The next step is to choose a shape. London blue topaz comes in many different shapes and cuts, so this is mostly a personal preference. However, if you plan to use this gemstone everyday, maybe consider a cut that does not show off the facets as it could make it more susceptible to cracks or scratches.

Lastly but not least, check the quality of the stone and the quality of the seller. Ensure that your seller can offer you certifications from the GIA or any other reliable source if the piece has diamonds. It's best to buy from an online source that has good reviews.


What is the difference between blue topaz and London blue topaz?

The difference between blue topaz and London blue topaz is that the color of London blue topaz is not natural. It is created with the help of irradiation and heat treatment to achieve a darker hue.

Does London blue topaz occur naturally?

No, London blue topaz does not occur naturally.

Are all London blue topaz stones irradiated?

Yes, all London blue topaz stones are irradiated. It is the only way that they can achieve that London blue hue.

Can you wear London blue topaz every day?

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