What So Special About Blue Diamonds

Arguably the best-known variant in the coloured diamond family, the blue diamond holds that top place as the visually most captivating gemstone. Whilst not the rarest nor the most expensive coloured diamond in the market, blue diamonds remain a top and for many an elusive choice.

In this Education page we will explore the unique features of blue diamonds, learn about what set this variant in the coloured group of diamonds apart, and what should you consider if you are considering going for this top fancy coloured stone.

What are Blue Diamonds?

In the world of diamonds, there are two main categories: colourless diamondsor white diamonds and coloured or fancy diamonds. Colourless diamonds are the most common variety, and the one that we associate with top gemstones and fine jewellery. Now when it comes to diamond classification, a number of other factors to consider. It is interesting to note that diamonds, besides the presence of colour, are categorised according to other criteria. Thus diamonds are divided into four headings.

• Type Ia

• Type Ib

• Type IIa

• Type IIb (Blue Diamonds)

Type Ia is the most popular variety and includes well-known colourless diamonds. Type Ib refers to the next category of diamonds that features the lightest presence of hues. This includes the range of yellow diamonds, or the diamonds feature lighter tones. Type IIa contains the rarer varieties of diamonds. Notably the lighter pink variants. The blue diamond variant that we are considering falls into the Type IIb category which is the rarest group of diamonds. These stones make up less than one per cent of gemstones.

The Story Behind Blue Diamonds

When it comes to blue diamonds, the main standout feature is the colour. And they stand out for more reasons than one. First considering that blue is a relatively rare hue in nature, and is considered a symbol of value and style in the diamond world, a gemstone that combines rarity, and the natural qualities of the diamond.

Now when it comes to blue diamonds, like any fancy coloured diamond, the story lies in the specific hue. Colour, particularly in its pronounced form as it is found in this category of gemstones, besides the various shades of yellow, is not common. With blue diamonds, the source of their colour is the element boron. Now unlike other blue-coloured gemstones like sapphires, where the colour in gemstone is a function of the presence of trace minerals such as iron and titanium. When it comes to blue diamonds, the cause of the distinct hue changes that take place in the stone at the atomic level and structural levels. 

The Role of Boron in Blue Diamonds 

The formation of the diamond stone takes hundreds of miles under the Earth’s surface and takes place over tens to hundreds of millions of years. During this process, the carbon atoms unite and hardened forming the famous covalent bonds that characterise diamonds. However, during this process, certain inconsistencies can occur. Notable is the defections that occur in the crystal lattice structure. It is at this point that the determining factor, the element boron enters the equation. The presence of boron gives rise to the blue colour of this diamond type.

The rarity of blue diamonds is a function of two factors: one is the rarity of boron in nature. Which is partly due to a lack of fuller understanding of their chemistry. Next is the rarity with which boron is present in diamond-forming regions of the world. Thus when these two elements carbon and boron meet in the harsh conditions of high heat and pressure, work to give rise to blue diamonds, one of the rarest and most captivating gemstones in the world.

When it comes to the emergence of the specific colour, since the colour is a function of the relationship between light and the type of material in question: in diamonds boron works by absorbing certain light waves, notably yellow, and in turn helps reflect blue light. Producing a distinct blue hue. The type of blue that is visible, in terms of concentration, vibrancy and tone varies with respect to the level of boron in the diamond.

Factors to Consider when Buying Blue Diamonds

Colour is naturally the most important factor when it comes to buying blue diamonds. With the gemstone that features richer blue hues being the most sought-after. Nonetheless, the core factors that determine diamond value remain: the 4Cs of diamonds which measure diamond quality based on its carat, cut and clarity with the exception of colour are measured the same way. With colour, however,  it is the presence of colour and the level of concentration that matters in determining the value of the gemstone.

When it comes to coloured diamonds, the price point is generally much higher. This is to be expected. As natural fancy coloured diamonds are among the rarest gemstones in the world, with the blue variant being among the top choices. And getting hold of them is not always straightforward as such gemstones are generally reserved for sale at gem auctions, or only available from special gemstone outlets which specialise in diamond gemstones and jewellery. So the buyer best be prepared, with 1.00-carat blue diamonds with high clarity going into the $ 100,000 range. So those in the engageement ring market need to be prepared.

A key consideration when it comes to blue diamonds, one that corresponds to their colour, is the presence of secondary hues. When it comes to coloured gemstones the purity of the single hue is a major selling point, and the presence of secondary shades like light green or even yellow weakens the quality of the stone. Hence top blue diamonds feature a uniform blue hue and are the best choice.

Blue Diamond Countries of Origin

When it comes to the sourcing of these diamonds, blue diamonds are only sourced from a handful of countries. Considering that diamonds are only sourced from a number of diamond mining countries in the world, with many of them stationed in Africa and other major gemstone and resource mining nations in the world. When it comes to blue diamonds the nations that lead the way are Australia, South Africa, and to a lesser extent India.

When it comes to India, historically was a major diamond-producing nation and today leads the way in the diamond trade and jewellery. With the mines in the region of Golconda continue to be a source of new stones. Though the supply is very limited. The Argyle mines in Western Australia historically led the way in coloured diamonds, notably in pink and red diamonds. Blue diamonds were also sourced but in lower quantities. With the closing of this mine, things have started to shift. Today South Africa remains a major supplier, though the availability of gem quality gemstones is still thin in contrast to the colourless variety.