The World is Your Oyster

The AnchorCert Gemmological Office is the UK authority on natural pearls and is the preferred choice of the industry for the identification of natural pearls.

Using in-house X-Ray equipment, the laboratory identifies:

The culturing of pearls is a constantly evolving process. The Japanese made a huge turn in the wheel of evolution when they perfected the process in the early 20th century but in the last 15-20 years the Chinese have taken over their mantle and moved it on again and we are now seeing pearls in sizes, shapes and qualities that simply didn't exist  twenty years ago.

One of the main developments has been in the production of freshwater pearls, which were traditionally considered inferior to their saltwater cousins. Freshwater pearls used to be small and shaped like rice crispies – but now thanks to new techniques and the hybridization of mussel varieties to create bigger types – they can be up to 16mm in size and perfectly round, so to the untutored eye it can be difficult to distinguish them from the larger South Sea varieties and this is undoubtedly having an impact on the market.

All cultured pearls are created by introducing a foreign body or nucleus (either a solid bead or some tissue) into the mantle tissue of an oyster or mussel. The creature then coats this with layers of mother of pearl or ‘nacre’ – a substance which occurs naturally inside its shell, to create a pearl. This process happens naturally in the wild and prior to pearl farming was responsible for the creation of the now increasingly rare natural pearl. Generally speaking, the deeper the layer of nacre the greater the luster of the pearl and the more its value.

Freshwater pearls are wonderfully adaptable and seem to offer more possibilities in terms of shapes and sizes than pearls of seawater origin. One example of this is the fact that freshwater pearls have stolen the clothes of the Akoya pearl and can now be created using a mother of pearl bead nucleus.

Another interesting example of their adaptability is the now popular ‘Keshi’ pearl. Keshi pearls (‘Keshi’ means poppy seed in Japanese) are highly irregular in shape and resemble  nuggets of hot metal dropped into water. They are produced in both oysters and mussels, as a by-product of the culturing process, but the Chinese have now discovered that if after harvesting a crop of pearls they return the mussels to the water they will create a second crop of Keshi pearls, without the need to introduce a new nucleus.

It seems that the mussel has a cellular memory and continues to do what it did when the previous pearl was present despite the lack of the nucleus. This means that the second harvest of Keshi pearls is far closer to a natural pearl than one that has been nucleated.

Colour

Once upon a time pearls were small and creamy or pinky white, now coloured pearls are all the rage. So where do these new colours come from? The answer is different types of oyster or mussel. The ‘black lip’ oysters of Tahiti and the Cook Islands give deep black/green, aubergine and pewter shades, while the ‘Gold Lip’ and ‘White Lip’ oysters give, as their names suggest, more golden or silvery pearls. South Sea pearls – the most valuable of all – tend to be silver/white to creamy champagne and gold. While Akoya (the original cultured pearl) tend to be white/pink/cream to silver grey. Freshwater pearls are generally white but can naturally be pink, peach, lavender or salmon.

However, not all pearl colours are natural. At the cheaper end of the market some pearls are dyed or stained to produce different colours and the use of silver nitrate and other techniques to produce greys and blacks is common practice. Some pearls are also being irradiated or heated to create darker fancy pearls but it is too early days to know what the long term effects of this are likely to be.

      Five reasons to think pearl

• With the current high price of gold price of gold, pearls are great value and provide stylish jewellery at competitive prices.
• Ethical jewellery is in the spotlight and pearls have  great ‘green’ credentials a to farm pearls successfully the water must be completely pollution free.
• Pearls are naturally beautiful without the need for faceting or cutting.
• If they are looked after carefully, regularly re-strung and cleaned using only mild detergent pearls last forever.
• Pearls are versatile and offer plenty of opportunities for complementary add-on sales