How to choose? Here we present a brief guide to the qualities of gemstones, and how to buy them, starting with diamonds.
The value of a diamond depends on an assessment of the four Cs—that is, carat, cut, clarity and colour. Carat indicates the weight of the stone; a carat corresponds to 200 milligrams (about 1/140th of an ounce).
Cut refers to the cutting of the diamond. The cut should be of excellent quality with facets at specific angles so that it perfectly reflects the light and creates a ‘fire’ inside. A diamond with at least 56 facets, a table and a point may be called a brilliant. That does not mean other cuts are less precious, for there are many ways to cut a stone and to bring the best out of it. Whether round, tear-shaped, oval or cone-shaped, the most important requirement is that the cut should be appropriate to the stone.
Clarity refers to the purity of the stone. The number, size, and location of any inclusions, transparency, and possible structural irregularities are assessed. In addition, a distinction is made between defects visible to the naked eye and those that can be seen by a 10-power magnifying loupe. The highest grading is FL for ‘flawless’. Then comes IF, ‘internally flawless’, meaning that no inclusions are visible with the same magnifier. The grades below include VVS, ‘very very slightly imperfect’, and VS, ‘very slightly imperfect’ with inclusions invisible to the eye, visible only with some difficulty with the magnifier; these do not affect the stone’s brilliance. SI, ‘slightly imperfect’ and I, ‘imperfect’, have inclusions that can be seen with the naked eye, and may affect the stone’s brilliance.
Diamonds are graded for colour, with the ideal being colourless. This is an important, sought-after characteristic because it allows the white light to penetrate the stone unhindered, emerging as a rainbow. Most stones are situated between ‘D’, which is ‘colourless’, and ‘Z’, which is light yellow. The colour is determined by comparing the stone with an internationally fixed number of master stones. So-called ‘fancy’ diamonds which may be blue, red, green or even black, are another story.
Most people think immediately of a velvety blue sapphire. The fact that this magnificent gemstone also comes in other colours was known for a long time almost only to insiders. In the trade, sapphires which are not blue are referred to as ‘fancies’. In other words, fancy sapphires are described as yellow, purple, pink, green or white sapphires.
Fancy sapphires are pure individualism and are just made for lovers of individualistic coloured stone jewellery. They are currently available in a positively enchanting variety of designs—as ring stones, necklace pendants or ear jewellery, as solitaires, strung elegantly together or as sparkling pavée. However, the sapphire has yet more surprises in store. There is an orange variety with a pink undertone which bears the poetic name ‘padparadscha’. Star sapphires are another rarity, half-dome-cut sapphires with a starlike light effect which seems to glide across the surface of the stone.
The sapphire belongs to the corundum group, the members of which are characterised by their excellent hardness (9 on the Mohs scale). Indeed their hardness is exceeded only by that of the diamond—and the diamond is the hardest mineral on Earth. Thanks to that hardness, sapphires are easy to look after, requiring no more than the usual care from the wearer, and excellent as engagement rings.
In earlier times, people believed that the firmament was an enormous blue sapphire in which the Earth was embedded. Could there be a more apt image to describe the beauty of an immaculate sapphire? This magnificent gem comes in all the blue shades of that firmament, from the deep blue of the evening sky to the shining mid-blue of a summer’s day. It also comes in other colours: the transparent greyish-blue of a distant horizon and the gloriously colourful play of light in a sunset: in yellow, pink, orange, purple and green. Sapphires really are gems of the sky.
The sapphire is strongly linked with feelings of sympathy and harmony, friendship and loyalty: feelings which embody composure, mutual understanding and trust. That is one of the reasons why women in many countries wish for a sapphire ring on their engagement. The sapphire symbolises loyalty, and at the same time it gives expression to love and longing. Green sapphire in particular symbolizes tranquility and calmness. A green sapphire’s significance is also associated with trust, loyalty, and integrity. It’s often thought that those who wear green sapphire jewellery are encouraging love, thoughtfulness and peace.
Gemstones in the corundum group consist of pure aluminium oxide which crystallised into wonderful gemstones a long time ago as a result of pressure and heat at a great depth. The presence of small amounts of other elements, especially iron and chrome, are responsible for the colouring. However, this does not mean that every corundum is also a sapphire. For centuries there were differences of opinion among the specialists as to which stones deserved to be called sapphires. Finally, it was agreed that the ruby-red stones, coloured by chrome, should be called ‘rubies’ and all those that were not ruby-red ‘sapphires’.
Sapphires lie well hidden in just a few places, and have to be brought to light through hard work. The best are found in Burma, Kashmir and Ceylon (Sri Lanka), although they are also found in Thailand, Vietnam, Australia, Brazil and Africa. From the gemstone mines, the raw crystals are taken to cutters, to be turned into sparkling gemstones by skilled hands.
When cutting a sapphire, the cutter has to muster all his skill, for these gemstones are not only hard. Depending on the angle from which you look at them they also have different colours and intensities of colour. So it is the job of the cutter to orientate the raw crystals in such a way that the colour is brought out to its best advantage.
The oldest sapphire finds are in Ceylon, or Sri Lanka as it is known today. There, people were already digging for gemstones in ancient times. The specialist recognises Ceylon sapphires by the luminosity of their colours. Having said that, most sapphires come from Australia or from Thailand—the Club sapphires, however, are all mined in Ceylon.
Their value depends on size, colour and transparency. With stones of very fine quality, these are, however, not the only main criteria, the origin of the gem also playing a major role. Neither is the colour itself necessarily a function of the geographical origin of a sapphire, which explains the great differences in price between the various qualities. The most valuable are genuine Kashmir and Burmese sapphires, the political problems in both rendering them scarce, and then come the sapphires from Ceylon. The possibility of the gemstone’s having undergone some treatment or other is also a factor in determining the price, since gemstones which can be guaranteed untreated are becoming more and more sought-after in this age of gemstone cosmetics. (The Club’s sapphires are untreated.)
To view more sapphires, for expert advice, and to request an appointment with a sapphire specialist in Hatton Garden, call us on 020 7399 2960. Whether a piece is bespoke for your particular requirement, or simply seen and purchased via our website, it will have been hand made by our Hatton Garden specialists, and the advantageous CountryClubuk price is likely to be saving you literally thousands of pounds, together with full 100% moneyback guarantees and valuation certificates at the full retail prices.
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Or call us on 020 7399 2960 to discuss your request or book an appointment with our Hatton Garden jeweller.