Our Guide to Pearls

Natural pearls are formed within the shells of soft shelled molluscs such as oysters. When microscopic foreign objects enter the mollusc’s shell they irritate the creature’s soft interior, and are surrounded by a film of nacre – the same material that gives the interior of the creature’s shell the iridescent shine known as mother of pearl. Over time the nacre hardens in layers around the irritant, and the pearl begins to grow larger.

Whilst we know that nacre forms in this manner science has still to understand the exact process. The chemical processes that create sapphires, rubies, emeralds and even diamonds have been synthetically replicated in a laboratory, but this is not the case for pearls.

For many years the only way to acquire pearls was by diving down to the beds where molluscs live and prying open every one until a pearl was found. Their incredible rarity meant that this very seldom led to the discovery of a pearl, and would kill many hundreds of the creatures in the process.

As pearls are organic-inorganic hybrid materials that are created within living creatures they come in a great variety of forms. Whilst the most desirable are completely spherical with a pale iridescence they come in an array of different shapes and types.

Baroque Pearls

Although the most recognisable pearls are spherical they can form into a great many different shapes. Smaller irregular pearls are often of little value, notable only as curiosities, but larger ones are known as Baroque Pearls, and are often embedded into distinctive and inventive pieces of jewellery.

Unlike spherical pearls, which can be presented in strings of graduating size in necklaces or bracelets baroque pearls are each totally unique, and so are often mounted in isolation in pendants or as earrings if two similar specimens can be found.

Seed Pearls

Seed pearls are extremely small pearls which have not acquired the mass to be worked into larger pieces of jewellery. When the pearl-bearing creature has been opened to extract the pearls they cannot be returned to the ocean to continue making seed pearls larger, so jewellers have found uses for these smaller variants.

Seed pearls are often paired with other gemstones and arranged to augment the visual effect that the jeweller is attempting to bring out. They often pair well with diamonds as the contrast between the nacreous iridescence and the completely clear scintillation of the pearl and diamond respectively creates a unique effect.

These pearls are also included in many pieces of Suffragette Jewellery, where they are paired with green Peridots and violet amethysts, together standing for the central goal of the movement – “Give Women Votes”.

Cultured Pearls

Cultured or farmed pearls are created with human intervention, usually with the implantation of tiny pieces of tissue from a donor shell into the mantle of a living oyster or mussel. These pearls are chemically identical to naturally formed pearls, although the layers which form within are distinct enough that they can still be differentiated.

Some cultured pearls are created without grafts. These pearls are often known as freshwater cultured pearls, and are similarly chemically identical, but have a cavity at the centre, making them a little lighter than true natural pearls.

Farming pearls is a relatively recent development. Commercial operations began in 1916, but the first true crop was not reported until 1928. This meant that for the majority of modern history there was no way to create a pearl.

Imitation Pearls

Like many of the most desirable gemstones throughout history the pearl has inspired many to attempt the creation of imitations. Some methods are more sophisticated than others, and as technology has advanced they have changed radically. Some of the more prevalent techniques are detailed below:

Plastic Pearls are created from artificial polymers, which are formed into beads and coated with a pearlescent material. They are extremely cheap to manufacture, but are also extremely easy to differentiate from true pearls or more sophisticated imitations. Whilst visual comparison may be sufficient to determine that a plastic pearl is not a pearl it can also be detected by differences in weight. The most common method of determining whether a pearl is a true pearl is to gently rub it against the front of the examiner’s tooth. True pearls are partially organic, and will feel gritty, whereas a plastic pearl is completely smooth.

Bohemian Pearls are created from cut and buffed protuberances of mother of pearl, the material present on the inside of mollusc shells. As mother of pearl gets its iridescence from the same material as pearls, nacre, bohemian pearls cannot be reliably identified by the tooth-test mentioned above. Versions also exist where the nacre material has been powdered, heated and compressed to shape.

Glass Pearls are either constructed from a bead of glass, or a hollow glass sphere filled with wax. In both cases the outer layer is sprayed or dipped in a pearlescent material. These imitations are closer to the weight and feel of true pearls than bohemian or plastic variants, but can usually be spotted by a sufficiently experienced assessor.

Cotton Pearls are manufactured from compressed cotton, and are sometime known as “Utter Ethical Pearls” as they contain no trace of animal material and are therefore manufactured without harm coming to any shellfish.

Types of Pearl Jewellery

Pearls have been mounted in a great variety of different items over the years, but the most immediately recognisable is a string of beaded pearls. Such strands can be worked into pearl necklaces or bracelets, and can be comprised of an array of similar sized and shaped pearls, or carefully selected so that the strands increase in size at the foremost part of the item.

Particularly large natural pearls or those with remarkable colouration and texture may be too grand to include in a string, and the jeweller may choose to build a unique piece around a single specimen. The extreme value of these pearls means that they will often be paired with other high-value gemstones or materials. In the example below the jeweller has paired a magnificent saltwater pearl with a sizeable old European cut diamond, along with an array of smaller diamonds, all contained within platinum metalwork to create a truly beautiful piece.

The spherical ideal shape of a good quality pearl may not lend itself to the crafting of particular pieces of jewellery, and it is down to the jewellers own skill and creative decisions as to how they can make them work in new forms. In the example below the central pearls have been bisected so that they can lie flat against the finger. This means that the pearls are less exposed, and can be protected by the gallery. It also means that the other side of the pearl can be used to craft another item.

The baroque pearl is much harder to craft into jewellery than more conventional shapes as the piece must be built around the natural irregular shape into which the pearl has formed. Jewellers often choose to build the shape into the larger design, using precious metal and stones to create a depictional item. In the example below a baroque pearl has been outfitted into an adorable pendant brooch in the form of a teddy bear.

At Antique Jewellery Online we have spent many years scouring antique markets to find the most remarkable and interesting items for our customers. You can view our full collection of pearl jewellery here to see our full inventory of pieces from the Georgian, Victorian, Edwardian and Art Deco periods.

Do you have questions about a specific piece? Feel free to get in touch with us at enquiries@antiquejewelleryonline.com or via telephone on England: +44 (0) 333 700 4500. Our team of experts is always happy to help you to get to know your perfect piece!