London blue Topaz is one of a few different types of blue gemstone that has a good level of hardness. These gemstones are low in cost which makes them extremely popular. Other blue gemstones which may be cheaper types are usually a saturated blue color and include lapis, kyanite and fluorite. These stones however are cheaper because they are softer which makes them less suitable for jewelery that is worn everyday such as a ring. Topaz on the other hand is a very durable gemstone
In the business of jewellery making and selling, blue topaz is among the best sellers. On the Mohs scale it sits at a number 8 which makes them unusually strong for the price. You can purchase blue topaz in a range of tones which all have different names. They are:
- Sky blue topaz
- Swiss blue topaz
- London blue topaz
As the blues become more saturated with color the price raises, with London Blue Topaz being the most expensive and valuable to collectors and jewellery buyers.
London Blue Topaz Colors
The London blue topaz stone comes in a dark grey blue color which some people liken to steel and even ink. Lots of the stones also have a slight green tone when they are looked at from different angles. Normal topaz is abundantly available, but with London blue topaz it’s rarer because of the coloring. The majority of blue topaz available is not totally natural, but instead is the cheaper white topaz which is then turned blue by means of radiation treatment.
The majority of gems that are available on the market including sapphire get their coloring from the elements they contain including iron levels. Others are colored by their composition of chemicals, but with topaz it is radiation that changes its color from white to blue. Naturally it is colored because of its ‘color centre’ which are essentially tiny imperfections in the lattice of the crystal which cause the crystals to absorb light in different ways so that they appear in various shades of blue.
London Blue Topaz Treatment
Outside of the natural environment London blue topaz is created by exposing white topaz to radiation within a nuclear reactor. Once the fast neutrons are introduced to the topaz the radiation makes changes to the color centres. This gives the London blue topaz you see in many types of jewellery. To make the blue lighter the stone is treated with heat which stops it from being a dark ink color. To ensure the stone is safe it is stored to ensure the radioactivity is at a level deemed safe. This usually takes place for several months before it is turned into jewellery. There are lots of rules to ensure that the stones are safe before they can be cut and handled by any dealers or sold on to the general public so they are perfectly safe and make a great addition to any outfit as part of an accessory. They look great set in an abundance of metals including gold, silver and titanium and give you a whole different look than the commonplace gems.