A World of Colour
While colourless diamonds are generally valued for how little colour they display, coloured gemstones are judged very differently. Here, colour is at the heart of both beauty and value. Hue, tone and saturation are among the most important factors, and colour alone can account for a significant part of a gemstone's overall value. Carat weight, cut, clarity and origin also play an important role.
Rarity is equally important. Gemstones that combine exceptional colour with limited natural availability can command remarkable prices on the international market, particularly when they come from a highly regarded geographical origin.
Yet the beauty of a gemstone is also deeply personal. Choosing a stone is not simply a matter of grades and measurable qualities, but also of the colours you are drawn to, the character of the individual stone and the meaning it holds for you.
Corundum – Ruby and Sapphire
Ruby and sapphire both belong to the corundum mineral family, one of the hardest naturally occurring minerals. With a hardness of 9 on the Mohs scale, corundum is second only to diamond.
Ruby owes its characteristic red colour to traces of chromium and is among the most valuable coloured gemstones in the world. Often referred to as the “king of gemstones”, the finest rubies are prized for their rich, intensely saturated red colour. The celebrated “pigeon’s blood” red is particularly associated with rubies from Myanmar. Exceptional examples can command some of the highest prices per carat of any coloured gemstone.
Sapphire is best known for its blue colour, which results from the presence of trace elements, particularly iron and titanium. However, sapphires occur in a much broader spectrum of colours, including green, yellow, pink, orange and violet. These are commonly known as fancy-colour sapphires. Pink sapphire, for example, offers an attractive alternative to pink diamond, often making it possible to choose a larger stone at a considerably lower price.
Among the rarest varieties is the padparadscha sapphire, prized for its distinctive blend of pink and orange. Traditionally associated with Sri Lanka, these exceptionally rare sapphires are highly sought after by collectors.
Quartz – Amethyst, Citrine and More
Quartz – Amethyst, Citrine and More
Quartz is one of the most abundant minerals on Earth and occurs in a remarkable variety of colours and forms. Among its best-known gemstone varieties are amethyst, citrine, rose quartz, smoky quartz and rock crystal.
With a hardness of 7 on the Mohs scale, quartz is suitable for many types of jewellery. Found throughout the world, it is valued for its wide range of colours and varying degrees of transparency.
Amethyst is recognised for its violet to purple colour and has a long history of association with royalty and religious symbolism. Despite its rich colour and historical significance, amethyst is generally more accessible than many rarer coloured gemstones.
Citrine is the yellow to orange variety of quartz, appreciated for its warm hues and typically high clarity. Both amethyst and citrine are generally transparent, often with few inclusions visible to the naked eye.
Rock crystal is the colourless variety of quartz, valued for its transparency and clear, understated appearance.
Topaz
Topaz occurs in a broad spectrum of colours, from colourless and pale blue to yellow, pink and reddish tones. The rarest and most valuable varieties display natural red or orange-red hues, while colourless topaz is considerably more common.
Blue topaz is widely used in jewellery, although its colour is usually achieved through the treatment of naturally colourless topaz. This process produces the distinctive shades of blue for which the gemstone is known today.
Beryl – Emerald, Aquamarine and Morganite
Emerald, aquamarine and morganite all belong to the beryl family and are among its best-known gemstone varieties. Their distinctive colours set them apart, from the rich green of emerald to the delicate blue of aquamarine and the soft pink and peach tones of morganite.
Emerald is prized for its characteristic green colour. Lighter green varieties of beryl generally do not meet the colour criteria for emerald and are instead classified as green beryl, which typically has a significantly lower market value.
Unlike many other gemstones, emeralds commonly contain natural inclusions. These are traditionally referred to as the stone's jardin, the French word for “garden”. Rather than being viewed simply as imperfections, they are widely accepted as part of an emerald's natural character and individual appearance.
Aquamarine takes its name from the Latin aqua marina, meaning “sea water”, a reference to its blue to blue-green colour. Aquamarine can form in large crystals with excellent clarity, making it possible to cut generously sized gemstones that often appear free from inclusions to the naked eye.
Morganite is the pink to peach-coloured variety of beryl. Its colour comes from traces of manganese and ranges from delicate pale pink to warmer peach tones.
The beryl family also includes heliodor, known for its golden yellow colour, and goshenite, the colourless variety of beryl.
