Jewellery Archives

Ancient cultures considered natural pearls to be ‘tears of the Gods’. They were believed to bestow mythical powers and wisdom to whoever possessed them. In today’s society the cultured pearl is considered the ‘stone of sincerity’ and represents purity. It symbolises the birthstone for June and the third and thirtieth wedding anniversary. Jackie Kennedy once said ‘Pearls are always appropriate’.

A set of cultured pearls gifted to Marilyn Monroe in 1954 by Joe Dimaggio

Yet for many years pearls have fallen out of fashion, with people associating them with their grandmothers and the older generation. However, as with the cyclical nature of all things, pearls are now enjoying a renaissance. Iconic women such as Michelle Obama can be seen wearing both a classic cultured pearl necklace as well as more contemporary cultured pearl set jewellery. The Duchess of Cambridge often sports a pair of cultured pearl earrings.

Cultured pearls are making a comeback but not just in the traditional sense of the simple necklace and stud earring set. The classic string of cultured pearls, such as the set gifted to Marilyn Monroe in 1954 by Joe Dimaggio (pictured), will always have a place in our hearts, however we appear to be moving away from the need for a string of perfectly round pearls and contemporary designers are embracing the irregular shapes of baroque pearls to make innovative and unique pieces. Freshwater cultured pearls such as the fireball are being combined with diamonds and gems to make beautiful, abstract creations.

The production of pearls is a fascinating business. Whether the end product is perfectly round or completely irregular in shape the process is the same.

When it happens naturally a ‘foreign body’ invades the mollusc and as a way of protecting itself the mollusc secretes nacre. Gradually layer upon layer of this lustreous substance containing microscopic crystals of calcium carbonate, covers the ‘foreign body’ and a natural pearl is formed. When it happens artificially and a piece of mantel tissue or bead nucleus is inserted into the mollusc the pearl is cultured.

It’s of little wonder that before Mikimoto commercialised the cultured pearl industry in the late nineteenth century, pearls were only accessible to royalty and the very rich. This is because of the many mollusc varieties known to us only a small number can produce pearls. Of the pearls that they produce only a small number will be of a desirable shape, colour and quality, and only a fraction of these will actually be discovered by man. Consequently natural pearls are extremely rare and very expensive.

So how can you tell the difference between natural and cultured pearls? If you take a look at the drill hole you may be able to see the bead nucleus of a cultured pearl. A factor in the value of natural pearls is weight, so the drill hole tends to be a lot smaller compared to cultured pearls. Also a string of naturally formed pearls will tend to be slightly mismatched and irregular in shape, they will be smaller and almost always graduated. However to be absolutely sure the pearls need to be sent to a laboratory for certification, where they will be x-rayed.

In 1937 the Yaguruma, a sash clip with interchangeable settings in 12 different forms, attracts crowds at the Paris Expo. Its unique design is a breakthrough in multi-functional jewellery. Sold in Paris, it disappears from public view, then reappears at an auction in New York in 1989. It is purchased by Mikimoto Pearl Island where it remains today.

There are many different types of cultured pearl but they fall into two categories and are either saltwater or freshwater.
Freshwater cultured pearls are cultivated in mussels, in lakes and rivers. Mantle tissue from another mussel is often used to start the process and this is why they are often irregular in shape. However bead nucleation is becoming more and more common in order to cultivate larger more rounded pearls. Up to forty freshwater cultured pearls can form within a single mussel, making them more readily available on the market.
To cultivate saltwater cultured pearls is a slightly more labour intensive process. They are grown in a variety of oysters. Often just one pearl per oyster, using both mantle tissue and a bead nucleus to produce a more round pearl.
There are three main types of saltwater cultured pearls: Akoya, South Sea and Tahitian. Akoya cultured pearls are farmed in Japan, China and Vietnam. They are usually white and cream in colour and measure from 2mm to 11mm.
South Sea cultured pearls are grown in Australia, Indonesia and the Philippines. They come in shades of white, silver and gold and typically measure from 8mm to 20mm.
The Tahitian cultured pearl are cultivated in French Polynesia and The Cook Islands. They are much darker in colour, blacks, greys and browns and measure from 8mm to 18mm.

This natural pearl and diamond necklace was recently valued for the purpose of insurance at £10,000.

Pearl jewellery is often passed down through generations and many people are unsure if it is natural, cultured or imitation.
When we consider that cultured pearls have gone up in value by approximately 10% over the last 5 years, and South Sea cultured pearls have gone up even more significantly, the question is, does your inherited pearl necklace have an accurate, up to date valuation and is it properly insured?

Laboratory-grown diamonds have been around for about 20 years but they have always been more expensive than the natural product and some have appeared in very unnatural colours. Techniques have improved and will continue to do so and prices have therefore dropped considerably.

De Beers have just launched their own brand of laboratory diamonds called their ‘Lightbox’ range – and are building a new factory in Oregon with a production target of 500,000 carats a year. They have indicated a retail price of $200 for a ¼ carat and $800 for a 1 carat stone which, despite sounding low, will still provide them with a larger profit margin than for their natural products. A reasonable ¼ carat natural stone would retail for £500 + today in the UK and a reasonable 1 carat natural stone from about £3500.

There are 2 very ‘high tec’ processes which can grow the diamond from a pure carbon ‘seed’ to over a carat in weight in about 5 weeks as opposed to the natural product which takes millions of years deep in the bowels of the earth. Man-made stones are not all totally flawless; internal flaws in natural stones are normally specks of uncrystallised carbon, whereas in man-made stones the flaws are caused by slight production glitches and variations in conditions can influence the colour and clarity qualities.

Laboratory grown diamonds

De Beers have said that they will laser mark every stone they produce, then ticket and retail it accordingly. The question is, will all producers and retailers be as honest and transparent? Another consideration is the practice of ‘diamond sights’, which take place during the early stages of the production of a piece of diamond jewellery. This is where a few very select bulk diamond buyers are offered large quantities of stones in huge ‘lots’, by the big diamond suppliers. Recently in India, a ‘sight’ was found to include only 10% natural against 90% man-made stones – with no indication from the supplier that this was the case.

Will these laboratory-grown stones drag the price of natural stones down or will it be an opportunity to promote their natural qualities and increase prices? Despite advertising to the contrary, diamonds are not that rare and although some new mines have opened in Middle Africa there have been no major new diamond field discoveries since the ones in Canada nearly 20 years ago. De Beers calculate that there are only about 50 established legitimate diamond mines operating throughout the world. They predict that the effect of relatively cheap man-made diamonds on stone prices in general could mean the number of producing mines could drop by half in the next twenty years.

Currently a first-time engagement ring buyer looking for a 2-carat diamond ring will see a sparkling man-made single stone at £1500 and a visually identical natural stone at £7500. Most will buy on price in my opinion, but I sincerely hope I’m wrong. The problem for retailers, manufacturers and of course valuers is that these man-made stones are real diamonds – ie pure carbon – and will test as such when examined by hand held diamond testing machines.

So, with this size of price gap, for both the insured and the insurer, it is going to be very important to be as sure as possible about the stone’s origins. The type of inclusions (flaws) in a natural stone do look different from those in a man-made specimen so that will help when making a judgement. However, the age of the piece and its ‘family’ history will also prove helpful guidance factors. When appraising client’s new jewellery, the need to see a certificate and receipt from the supplier stating the stones’ origins or even better an independent laboratory certificate for the principal stones, is becoming increasingly more important to both valuers and insurers.

Colorless gem cut from diamond grown by chemical vapor deposition

Currently, the GIA (Gemmological Institute of America) which is the most recognised laboratory worldwide is saying that it will carry out stone inspections and will state if a stone is natural or man-made. In the case of a man-made piece they will state the carat weight, but they will not – at this stage – classify its colour or clarity. The other main laboratories like HRD and IGI have not yet made their positions clear but I would think they would follow GIA’s position. It is to be noted that there have been quite a few new ones emerging in the Middle and Far East, out of which have come some rather disturbing stories about the accuracy of their classifications.

Our recommendation is to stick to the well known and established laboratories. It is claimed that, say a 1 carat stone, E colour and VS1 clarity with a GIA certificate could be worth 10% more than an almost identical stone with a less high-profile laboratory certificate. However, unfortunately GIA do not have a UK laboratory currently.

The diamond trading market has changed enormously over the past 20 years with De Beers no longer in virtual ‘sole control’ and the Canadians and the Russians going their own way in marketing their diamonds. The monthly diamond Rapaport and Index reports, which list the average trade prices in US dollars of millions of loose diamonds of all sizes and qualities on offer throughout the world, are still used by the trade as their base point.

Making synthetic diamonds through high pressure

I think it’s too early to be certain which way the market will go. There are obviously wider and more general factors such as the economy and politics which may also have an impact, but for sure there’s uncertainty and nervousness in some areas of the market. The fact that De Beers have committed to their own production of stones, together with their prediction that the relative ‘cheapness’ of the man-made stones could halve mining and production of natural stones in the next 20 years, gives an indication of where they foresee the market heading. The other side of the coin is that in that situation natural mined stones will become rarer and rarer therefore the prices will rise.
In conclusion, the need for regular valuations of your diamonds is becoming increasingly more important.

Category Archives: Jewellery

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