Discover the Allure of Blue Gemstones: A Guide to Their Beauty

Dive into the mesmerising world of blue gemstones! Explore their enchanting beauty, unique properties, and the ideal choices for your collection.

The Science Behind the Colour Blue in Gemstones

The captivating blue hues in gemstones are a result of complex scientific processes that involve both the presence of specific elements and the interaction of light. These elements, such as iron, titanium, and copper, can cause a gemstone to absorb certain wavelengths of light and reflect others. For instance, the presence of iron and titanium in corundum results in the enchanting blue colour of sapphires. Similarly, trace amounts of copper in minerals can produce the vivid blue of turquoise. The science behind these colours is not only fascinating but also contributes to the uniqueness and allure of each gemstone.

When light enters a gemstone, it interacts with the atoms and electrons within the crystal structure. This interaction can cause certain wavelengths of light to be absorbed while others are reflected or refracted. The specific wavelengths that are absorbed or reflected determine the colour that we perceive. For example, when red and yellow wavelengths are absorbed, the remaining blue wavelengths are reflected, giving the gemstone its blue appearance. This process, known as selective absorption, is a key factor in the creation of the beautiful blue colours found in many gemstones.

In addition to selective absorption, the crystal structure of a gemstone can also affect its colour. The arrangement of atoms within the crystal lattice can influence how light is absorbed and reflected, resulting in variations in colour intensity and hue. For example, the presence of certain impurities or structural defects can enhance the richness of the blue colour in a gemstone. This intricate interplay between light and crystal structure adds to the mystique and charm of blue gemstones, making them highly sought after by collectors and enthusiasts alike.

To me, the word ‘blue’ conjures up the brightness of a summer sky, perfectly reflected in the light hue of a Swiss Blue topaz, or the freshness of the sea, as seen in a sparkling aquamarine. 

The best-known blue gemstone is, of course, sapphire.  Though sapphire comes in many different colours, deep, rich, royal blue is the most famous.  As seen in Princess Diana’s engagement ring gifted by Prince William to his then wife-to-be, Kate Middleton, sapphire has since soared in popularity as a stone for popping the question.  It’s a canny choice for an engagement ring, as sapphire is believed to encourage fidelity!

For those of you seeking a blue gemstone that’s a little more unusual, how about silky, blue kyanite?  Increasingly seen in jewellery since reserves of excellent quality were found in Nepal, kyanite is used as a less costly alternative to sapphire.  Kyanite is an interesting gem because it’s the most anisotropic of all gemstones. 

Anisotropic gems are gems whose hardness differs depending on how they are cut. This phenomenon is called hardness anisotropy. All gemstones are anisotropic to at least some extent, but kyanite measures only 4.5 to 5.5 on the Mohs scale when cut parallel to the longer side of the crystal.  When cut on the shorter side of the crystal, however, the hardness is 6 to 7, making it much more suitable for jewellery. 

British jewellery designer Monica Vinader currently has some gorgeous and affordable jewellery featuring kyanite

If you have deeper pockets and are looking for something really special, there’s nothing like Paraiba tourmaline.  Paraiba tourmaline is the most valuable variety of tourmaline and, since reserves in the Brazilian location of its original discovery have now run out, this gemstone is highly sought after. Occurring in shades of blue and green, Paraiba tourmaline’s startling colour comes from traces of copper. Arguably the most eye-catching shade is the almost neon Caribbean blue.  There’s certainly nothing depressing about this colour, though a large, high-quality Paraiba tourmaline could easily set you back as much as a 5* Caribbean holiday, or two!

Investing in Blue Gemstones: What You Need to Know

Investing in blue gemstones can be a rewarding but it requires careful consideration and knowledge of the market. One of the key factors to consider when investing in blue gemstones is their rarity and quality. Gemstones that are rare, possess exceptional colour, clarity, and size, tend to hold their value and appreciate over time. Sapphires, especially those from renowned sources like Kashmir or Burma, are highly sought after by collectors and investors due to their scarcity and superior quality.

Another important aspect of investing in blue gemstones is understanding the market trends and demand. Blue gemstones, such as sapphires, aquamarines, and turquoise, have consistently maintained their popularity and desirability. However, market conditions can fluctuate, and certain gemstones may experience periods of higher demand or increased value. Staying informed about industry trends, auction results, and expert insights can help you make informed investment decisions and identify opportunities for growth.

When purchasing blue gemstones for investment purposes, it is crucial to obtain certification and authentication from reputable gemmological laboratories. Certificates from institutions like the GIA or AGS provide detailed information about the gemstone's characteristics, origin, and any treatments it may have undergone. These certificates add credibility and value to the gemstone, making it easier to sell or trade in the future. Additionally, working with trusted dealers, jewellers, and auction houses can ensure that you are acquiring genuine and high-quality gemstones for your investment portfolio.

Kim Rix GG GIA

Gemstone Detective

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