Buyer's Guide

Emeralds are valued based on their luminosity and depth of colour. While inclusions often mar the evenness of colour, fine inclusions do not decrease an emerald’s value. On the contrary, even with inclusions, an emerald in a deep, lively green has a much higher value than an almost flawless, paler coloured emerald.

The master cut

While its hardness protects the emerald to a large extent from scratches, its brittleness and many fissures can make cutting, setting and cleaning rather difficult. Even for a skilled gem cutter, cutting emeralds presents a special challenge, firstly because of the high value of the raw crystals, and secondly because of the frequent inclusions. Emeralds are cut in many different ways, but a special cut has been developed just for this gem: the emerald cut. The clear design of this rectangular or square cut with its bevelled corners brings out the beauty of this valuable gemstone to the fullest, and at the same time, protects it from mechanical strain.

The ruby is the red variety of the corundum mineral, which also includes the sapphire. Pure corundum is colourless. As such, it is the slight traces of colour-creating elements such as chrome, iron, titanium or vanadium that are responsible for the ruby’s colour. As one of the hardest minerals on Earth, the ruby is second only to the diamond in its hardness. Only red corundum can be called ruby. Any other colour is known as sapphire.

Colour is everything

Colour is a ruby’s most important feature, with transparency as a secondary consideration. As such, inclusions do not affect the quality of a ruby, unless they decrease the transparency of the stone or are located right in the centre of its table. The cut is essential as only a perfect cut will underline the beauty of this valuable and precious stone appropriately.

Just like the ruby, the sapphire belongs to the corundum group and is the second hardest mineral on Earth. Because of its hardness, a sapphire is easy and simple to care for.

A sapphire can come in different colours, but blue is the most common. Sapphire blue has long been a colour related to anything permanent and reliable. It is for this reason that women in many countries settle on the sapphire for their engagement rings.

Opals shine and sparkle in a continually changing play of colours, which experts describe as “opalising”. Depending on the kind, place of occurrence, and colour of the main body, opals are differentiated as:

• Dark/Black Opal
• White/ Light Opal
• Milk/Crystal Opal
• Boulder Opal
• Opal Matrix
• Yowah Nuts from Queensland, also known as “picture stones“
• Mexican Fire Opal
• Common Opal (lacking the typical play of colours)

In order to best bring out the play of colour in a fine opal, the stones are cut and polished to round or oval cabochons, or any other softly domed shape, depending on the raw material. Only the best qualities of the Fire Opal, with its orange-red fiery shimmer, however, are suited for faceting.

Opal loves to be worn on the skin

Opals can turn brittle due to their water content – which is usually between two and six per cent. When stored in a place that is too dry or exposed to heat over a long period of time, opals will show fissures and the play of colour will become paler. Therefore, opal jewellery should be worn as often as possible so that the gemstone can receive the needed humidity from the air and the skin of its wearer.

This gem is mainly green but is also found in shades of white, grey, black, yellow, orange, and in delicate violet tones. Known to man for some 7,000 years, it was considered an ideal material for weapons and tools in prehistoric times. Even as early as 3,000 B.C., jade was known in China as ‘yu’ or the 'royal gem'. In the long history of art and culture of the expansive Chinese dynasty, jade has always had a very special significance, roughly comparable with that of gold and diamonds in the West.

What is jade?

'Jade' is a generic term for two different gems, nephrite and jadeite. But it was not until the beginning of the 19th century that mineralogists and gemmologists started to differentiate between them as they bear a considerable resemblance to each other in terms of their appearance, hardness and the properties they exhibit when being processed. Although both are tough, as they consist of dense, close-grained, matted aggregates, they differ from one another in their chemical composition and colours. Only in the very finest jade is the colour evenly distributed. Both nephrite and jadeite often have veins, blemishes and streaks running through them, though these may not always be regarded as flaws. On the contrary, some of these patterns are considered particularly valuable.

What distinguishes good jade?

In general, the value of jade is determined according to its:

• Colour
• Colour Intensity
• Vivacity and Texture
• Clarity
• Transparency

Preferences for particular colours vary from region to region and culture to culture. In the US and Europe, emerald green, spinach green and apple green are regarded as particularly valuable. In the Far East, on the other hand, pure white or a fine yellow with a delicate pink undertone is highly esteemed. In the world of jewellery, the fine violet nuances of lavender jade are very popular. It is, however, the rare emerald green of imperial jade that fetches the highest prices.

Fake or poor-quality products or stones that have been coloured or otherwise treated have been offered for sale. To ensure the integrity of your purchase, it is advisable to buy jade only from reputable dealers and jewellers. In recent years, creative jewellery and gemstone producers have come up with some wonderful modern jewellery designs to update the image of jade.