York’s Guide to Buying Pearls

White Autore South Sea Pearl Necklace  

Though not technically gems themselves, pearls are some of the most precious naturally occurring objects on earth, adored by humans for time immemorial. Believing these iridescent marvels were the tears of god, ancient Persians called them the ‘children of light’; Chinese sailors believed pearls owed their inimitable glow to moonlight trapped trapped within; awed Greeks adorned their statues and temples with them, and affluent Roman women wore their pearls to bed, so as to carry them in their dreams.

Natural pearls are birthed of unlikely and astonishing origins. Harvested from aquatic molluscs such as oysters, mussels, and clams, these precious treasures are formed when a foreign irritant breaches the creature’s shell and settles on it’s soft, delicate mantle. As a defence mechanism, the mollusc produces a curious, iridescent substance known as nacre – commonly known as mother of pearl – to coat the object. Over the years, layer upon layer, this miraculous substance encompasses the irritant and as it hardens, a beautiful pearl is formed. 

Exemplary of nature’s multifarious beauty and the protean nature of the sea, pearls are found in an array of colours, shapes, and sizes, and each of these characteristics have a marked influence on the cost and value. Unfortunately, the cost and value of a pearl don’t always match up. As with other precious materials, it pays to know a little about what you are buying into when buying pearls to avoid a bad deal; the modern market is flooded with cheap imitations and pearls of lesser value which are not always not always advertised as such. To help you make an informed purchase, and to ensure that you get the best product for your money, the knowledgeable gemologists at York Jewellers have put together a definitive guide to buying pearls.

 The Five S’s:

When buying diamonds, the Four C’s are your go to guide; when buying pearls, it’s the Five S’s: Shine, Shape, Size, Surface, and Shade.


Perhaps above all other factors, it is the beguiling iridescence of a natural pearl that informs its value. A pearl of quality will reflect and refract the surrounding light and seem to glow softly from within. Observing the pearl from different angles will reveal the quality of its shine, with precious pearls illuminating a spectrum of radiant and iridescent colours. By comparison, pearls of lesser value will appear dull and lifeless. In short, the higher a  pearl’s lustre, the higher its value, but unfortunately – due to developments in counterfeit technology – it is not always possible to discern a natural pearl from fake with the naked eye. This is one of the reasons to only buy pearls from a trusted and reputable source. Using a powerful magnifying glass, jewellery specialists can easily see whether a pearl is natural or counterfeit.


The shape of a pearl will significantly affect its market value.  Due to the fact that pearls are natural curiosities grown inside a mollusc, it is only natural that they are found in a wide variety of shapes influenced by a myriad of factors that occur during development.  Depending on their physical form, pearls are divided into the following categories: 

Autore South Sea Pearl and Diamond Ring 


As a general rule, it is said that the more spherical a pearl, the higher its value – as perfectly round pearls are the rarest form of natural pearls.  A pearl is deemed round only when the difference between its height and width is less than 2.5%. So, a pearl that measures 10mm can have up to 0.25mm variance and still be considered round.



The drop category encompasses a wide variety of forms including teardrop, oval and egg-shaped pearls, as well as the curiously beautiful semi-drop and cone-shaped pearls. The physical variations within this category a multifarious often dramatic, but the guiding principle is that the horizontal axis of the pearl is markedly shorter than the vertical



Circular pearl’s have a unique and truly astonishing beauty. Appearing as though they have been shaped by master craftsmen, these pearls have intricate grooves running in parallel around their circumference. A pearl may have one or many of these rings, and all other shapes can be classified as circle pearls if these curious rings are present.





Baroque pearls are as extravagantly beautiful and ornate as the name suggests. Born of nature and exemplary of the sea’s changeability, each pearl under this classification is entirely unique, and as curiously irregular as the next. With each pearl being so unique, jewellery made of baroques offers an abundance of personality. 



All good things take time, and depending on the varietal, pearls can take up to 2 - 20 years to reach maturityThe pearls that we use here at York Jewellers are the fabled Australian South Sea Pearls, the most coveted and valuable pearls in the world. Found off the rugged and wild north coast of Western Australia, these incredibly beautiful pearls take any where between 2-3 years to fully develop. The size of a pearl can be further broken down to surface area and weight. Pearls are weighed using a measurement known as a momme, an old Japanese unit of measurement dating back to the 1800's. One momme is equal to 3.75 grams or 18.75 cts.  Naturally, larger pearls will generally fetch a higher price tag, but a pearl's proportions also significantly influences it’s value. In some instances, two pearls of noticeably different sizes may be priced the same if the smaller is more proportionate. 

Autore South Sea Pear Stud Earrings 



Just like snowflakes, no two pearls are the same, each being born with its own unique characteristics and beautiful nuances. This aside, it is more or less a rule that pearls with a flawless surface have a higher worth. Any imperfections such as chips, cracks, scratch marks, dimples, bumps or wrinkles, will significantly lower the value of a peal. 

 Studying the surface of a pearl is instrumental in discerning its value. One trick is to rub the pearl ever so slightly against your front teeth. A true pearl will feel deceptively gritty – almost like an incredibly fine sand paper – whereas an imitation pearls will feel smooth like eggshell. While most jeweller's may not let you test the pearls against your teeth, they should be more than happy to verify if a pearl is legitimate using their own special instruments.



As is the case with diamonds, pearls come in a veritable spectrum of spectacular colours and shades, including deep forest-greens, royal blues and champaign hues. According to most jewellers white, gold and silver pearls are the most valuable, with those containing a greenish-yellow hue being of the least value. This colour criteria doesn't necessarily coincide with a person’s individual taste, so it’s possible to find some stunningly good buys out there

Searching for the perfect pearls? For more information on pearl jewellery, give us a call on (02) 4721 0780 or pay us a visit in store