Tagged with 'Pearl grading'

Buying and comparing pearl jewellery can be a difficult task. Here are the second 5 of ten simple questions to ask when buying pearls and to help find the right piece of pearl jewellery for you:

6. What size of pearls to choose?

It is more difficult and more expensive to produce a larger cultured pearl, particularly above 11mm in diameter. Some oysters such as the Akoya oyster are physically unable to produce a pearl that are larger than a certain size.

Each additional millimetre of diameter can significantly increase the rarity and value of a pearl, so it is important to think about the right size of pearl for you and the overall look of the jewellery. A pearl size between 7mm to 9mm is highly popular for a classic necklace, whereas a larger pearl size above 11mm can be much more of a statement luxury item.

If you are considering jewellery and prices from different retailers, make sure you compare the size of the pearls.

7. What shape are the pearls?

Pearls come in an astonishing diversity of shapes that can be classified as spherical, symmetrical or baroque. Perfectly round pearls form a small proportion of annual cultured pearl harvests and are more expensive.

Freshwater pearls, in particular, are unlikely to be round due to the method of culturing these pearls. Near round and symmetrical button freshwater pearls typically are more common and not as expensive. Baroque pearls are found in irregular shapes that can make them individual and exquisite, often showing a rainbow of colours on their surface.

Choose a shape of pearl that fits the jewellery design and your budget. If it is the look of a classic round pearl that you wish for, check first that they are indeed round.

8. Is the surface of the pearls marked?

A beautiful pearl, like a diamond, is a rare and expensive gem. Minor markings or spots on a pearl are quite normal and contribute to their character. Most buyers of pearls understand that a pearl may have small variations in surface, emphasising their individuality. More significant scratches, cracks and holes on the surface of pearls will impact their value and lifetime, even causing a pearl's nacre to break or peel.

Ask an experienced jeweller if you are considering buying pearls that are heavily blemished.

9. Don't forget the necklace length and the clasp

The price of your pearl jewellery will depend on the number of pearls used and the quality content of any metal that is designed into the jewellery such as silver, gold vermeil or 9, 14 and 18 carat gold. For centuries, pearls have also been matched in jewellery with precious and semi precious stones such as diamonds, agate, onyx and amethyst.

Always compare the length of a strand of pearls, understand the hallmarking of a metal and the precious or semi-precious stones used.

10. Does your retailer understand pearls ?

The diversity of pearls makes it a puzzling task to match pearls together for jewellery. This may often require access to a large stock of pearls. The better the pearls are matched based on size, shape, colour, lustre and surface quality, the more likely the jewellery will be balanced and beautiful.

Look for a specialist retailer with a reputable knowledge of pearls. Trade associations such as the NAJ can be helpful sources of information in finding a good local or online jeweller.

Pearl jewellery can be found in a wide range of designs, qualities, and prices. When buying pearls, retail and online shoppers can find pearl necklaces that range from just ten to tens of thousands of pounds in price. For this reason alone, buying pearl jewellery can be a daunting task.

Here are the first 5 of ten simple questions to ask to help find the right piece of pearl jewellery for you.  The second 5 questions are here.

1. Are the pearls natural, cultured or imitation?

Natural pearls are real pearls formed in wild molluscs living in their natural habitat without any human intervention. Their rarity has made natural pearls highly valued and a collector’s gemstone. Cultured pearls are also real pearls, but are grown after a pearl farmer has stimulated the development of the pearl in the mollusc. Cultured pearls are iridescent gems that can be worn and enjoyed every day. Fake pearls are made with a coated glass bead and are fun accessories, but do not have the same organic or luxurious feel of natural and cultured pearls.

Most pearls sold in shops or online will be cultured or imitation pearls. Pearls that are described as being natural will generally not be.

2. Are the pearls freshwater or saltwater cultured pearls?

The majority of cultured pearls available in the fashion market today are Freshwater pearls and are produced in volume in freshwater mussels, mostly in China. Saltwater cultured pearls are produced in a different variety of oysters, chosen for their quality, size, shape and colour. Akoya, Tahitian and South Sea pearls are saltwater pearls. Fewer saltwater pearls are produced each year and their cost is more expensive than that of freshwater pearls.

If the origin of the pearls is not specified, or if the price is comparatively low, then assume the pearls are freshwater or imitation pearls.

3. What is the quality grading of the pearls?

Unlike the diamond industry that uses the GIA’s International Diamond Grading System (the 4Cs), there is no single accepted industry grading system for pearls. Beware of product descriptions that grade a pearl as AAA+ or AAAA as these have no real accepted meaning. Many factors will influence the value of a pearl and some of these are listed below.

Ask your retailer how a pearl is graded and assess their level of knowledge and expertise before buying pearls.

4. Are the pearls dyed?

The colour of a pearl will reflect the type of mollusc that the pearl was cultured in, but may also be as a result of certain dyes, treatments and enhancements. A Freshwater Pearl might be dyed black or peacock so as to mimic the natural colour of a black Tahitian Pearl. A colour treatment may be used to disguise the poor quality of a pearl’s lustre or surface. Pearl jewellery, in which the colour of the pearls is uniformly matched, will possibly be dyed.

Ask your retailer if the pearls have been treated for colour as many dyes will fade or change colour over time.

5. How sharp are the reflections in the pearl?

The intensity of a pearl’s reflections is known as lustre and is absolutely unique to pearls, different to any other gemstone. When grading pearls, highly valued pearls will have a mirror-like, sharp and shiny lustre. Poor quality pearls without lustre will be dull, opaque and lifeless.

Lustre is one of the most important reasons for the differences in price between one pearl and another. Look for pearls within your budget that have the best lustre, as these will complement your skin and the face more beautifully.

The astonishing diversity of the pearl has made pearls a versatile gem of choice for all types of jewellery, in fashion and other accessories. But when buying and wearing pearls, should you pay attention to its shape?

The shape of a cultured pearl is determined by several factors when the pearl is developing inside the mussel or oyster. The most important of these are the shape of the nucleus used by the pearl farmer and the position of a pearl that is grown in the mollusk.

Gemmological experts at the GIA describe the shape of pearls using three categories.

1. A spherical pearl has a round or near round shape. This is the classic pearl shape. Perfectly round pearls can be quite rare, particularly with Freshwater pearls that tend to be near round as they are not grown around a bead.


2. A symmetrical pearl has a regular shape so that, if it is sliced in half, each half is a mirror image of the other. These pearls can have an oval, flattened button or drop shape.


3. A baroque pearl has an irregular and non-symmetrical shape. Pearls are described as semi baroque if they are not quite symmetrical.

Certain pearls also have grooves or ridged rings around their entire circumference and these pearls are referred to as circled.

The value of these pearls can vary widely, with a round pearl being generally considered the most valuable shape of a pearl. Perhaps traditionally this was because pearls were considered to be a symbol of the moon. But today, rarity and perfection are key drivers of value in a cultured pearl. For these reasons we would recommend that you buy pearls from a recognised pearl specialist.

Is shape a good guide to pearl quality? Not entirely. We love the quality and look of baroque pearls. Whilst not as valuable as round pearls, they can still make a highly individual and unique piece of jewellery.

There are also other important factors you should consider when buying pearls such as Lustre and Surface.

When describing the shape of a pearl, baroque is a term that is used to describe irregular and non-symmetrically shaped pearls that have been formed in freshwater mussels and saltwater oysters. Baroque pearls are not round, drop or button shaped.

The shape of a baroque saltwater pearl is caused by the uneven deposition of nacre by the oyster around its nucleus.

Up to 40% of the harvest of cultured pearls from a Tahitian pearl farm can be baroque in shape. These generally are found to be smaller in size, with true Tahitian baroque pearls greater than 12mm being very rare and sought after.

Larger Australian South Sea baroque pearls are also unusual and particularly beautiful, with a silver blue overtone and beautiful lustre.

Baroque pearls have been used for many years to create wonderful pieces of jewellery. One of the most famous historical pieces of baroque pearl jewellery is The Canning Jewel. To be found today in London’s Victoria & Albert Museum, it is believed to have been made in the 19^th century and uses a number of baroque pearls to create its mythical Merman figure.

Baroque pearls today are less extravagantly worn, but are still highly sought after for their individual shapes and colours. Today, baroque pearls are inspiring a new generation of contemporary fine jewellers, from Melanie Georgacopolous to Mizuki, drawn to their unique forms.

At Winterson, we stock a range of necklaces, baroque pearl earrings, sautoirs and bracelets made from Tahitian baroque pearls. Each pearl is unique and its contours, circles and peacock colour creates a sophisticated and highly contemporary look.

Is there an obvious difference between real and fake pearls ? Here are a few tips on how to tell real pearls from an imitation pearl.

It is often said that a factory-made pearl will be very smooth to the touch if passed against a tooth, whereas a natural or cultured pearl is more textured due to its layers of organic matter called nacre. We do not recommend this method as it can be damaging to the real pearl. Never be tempted to bite into the pearl itself.

Although specialist laboratories can provide an accurate assessment of a pearl by performing a range of tests including X-ray examination of the pearl itself, it can sometimes be possible in expert hands to identify excellent imitation pearls through touch and observation.

The density, weight and sound when you click imitation pearls together can be quite different to that of real pearls.

Another simple method used is to examine the drill hole in the pearl.

In contrast to natural and cultured pearls, the layering of varnish in factory-produced imitation pearls can often be readily identified at this point, perhaps by identifying some melting of the varnish at the actual drill hole.

The commercial sale of fake, faux and artificial pearls is quite common and many customers ask us about pearls that they have seen or been offered on holiday. For example, no pearls are cultured in Mallorca.

The techniques for creating imitation pearls were first developed in 17^th century France and the basic procedures are still in use today. A fish paste called ‘Essence of the Orient’ was made from salmon and herring scales, mixed with varnish and used to coat a hard bead such as alabaster or glass.

The resulting ‘pearl’ was dried and polished, before the process is repeated many times to form imitations of the layers of nacre that are found in a natural and cultured pearl.

Typically, these ‘pearls’ are uniform in appearance and don’t have the unique characteristics of colour, shape and blemishes that you will find in natural or cultured pearls that have been grown in a mollusc. More recently, better examples of fake pearls can be found.

We love the deep lustre of natural and cultured pearls. None of the pearls that we sell at Winterson are made using these imitation techniques.

If you have any questions about our jewellery, please do contact us.

A pearl's iridescence is known as lustre and is absolutely unique to pearls, different to any other gemstone. When grading pearls, highly prized pearls will have strong depths of colour and a shiny lustre. Without lustre, pearls can be dull, opaque and lifeless.

The factors that determine a pearl’s lustre are highly complex, being determined physically by the way that light diffracts through the physical structure of the layered nacre of the pearl. The thickness of the nacre is caused by how long the pearl is left in the oyster. Generally, pearls with the greatest thickness of nacre will have the deepest lustre.

The colour of a pearl mainly reflects the type of oyster or mussel that the pearl was cultured in.  However, a pearl’s complex overtones of colour can also be due to the temperature of the water, its cleanliness and even the plankton that the oyster feeds on. For example, colder water can introduce a light grey colour to a pearl and dirty water will create a brown overtone.

Unfortunately once the pearl is removed from the oyster, lustre doesn’t improve with age like a fine wine.

By selecting good quality pearls, and with careful cleaning, the lustrous qualities of a beautiful pearl can, however, be maintained over time. For more information, read our Buying Guide on how to take care of your pearls.