For years, pearls have been paired with popular gemstones like diamonds, emeralds, sapphires and rubies – creating striking jewellery designs celebrated for theirnatural lustre and radiance.
But is a pearl a gem in the same way as the jewels with which they’re so often paired? It’s time to crack open this mystery and uncover the truth!
Defining a gem
First and foremost, what exactly makes a gem?
A gemstone is a naturally occurring mineral that can be cut and polished for use in jewellery and other decorative applications. Gems are valued for a combination of their rarity, colour, lustre and strength (hardness).
Where once a gemstone referred exclusively to mineral-based jewels, the category has become more expansive over time. Organic materials likeamber (fossilised tree resin) andcoral (a marine animal) are now widely accepted as gemstones, even though they technically aren’t minerals.
This expansion in gemstone taxonomy answers our question of whether a pearl is a gem. Like coral or amber, pearls are not minerals – but they are widely considered as gems.
What is a pearl?
Pearls are formed inside the soft tissue of both freshwater and saltwater molluscs – typically an oyster or mussel. When a small irritant enters the mollusc’s shell, the mollusc will respond defensively byproducing nacre. If a mollusc doesn’t respond this way, it will die.
Nacre is made up of calcium carbonate (most commonly aragonite) and conchiolin (a flexible organic protein). Over time, layer upon layer of this nacre will concentrically develop around and over the intruder. This nacre coating eventually becomes the pearl, as well as the more abundantmother of pearl that lines the interior of the mollusc’s shell.
Nacre is what gives pearls their distinctive lustre and glow, reflecting light in a way that differs from other gemstones. Unlike other gems, pearls don’t need cutting or polishing. Each pearl is entirely unique – its colour, sizeand shape will differ depending onthe surrounding environment.
Pearls can also be cultivated. Where natural pearls are formed almost accidentally, without human intervention,cultivated pearls are produced when a human deliberately introduces an irritant to a mollusc’s shell, to help the pearl grow.
Pearls are revered in much the same way as mineral gemstones for a variety of reasons. This includes factors like lustre, beauty, rarity, cultural significance, cultural symbolism, value and desirability.
Organic gemstones – the scientific vs. cultural debate
Pearls are biological in origin, meaning that they differ from mineral-based gemstones as the only gem material formed in a living organism. In other words, pearls are created through biological activity, and are ‘biogenic’ in nature – unlike minerals, they’re not formed through geological processes.
That’s why the jewellery industry and gemological institutions (organisations dedicated to studying, grading and certifying gemstones and jewels) classify pearls as organic gemstones.
For example, the highly respectedGemological Institute of America (GIA) recognises pearls as gemstones, but distinguishes them from mineral gems. Scientific mineralogists can take issue with classifying pearls as ‘true’ gems because of their non-crystalline organic structure and origin.
However, gemological institutions typically make their evaluation based on factors beyond ‘just’ the chemistry and composition of a gem. Other variables like market value, use in ornamentation and cultural cache all play a role.
As such, although pearls are not gems in the sense understood by mineralogy, they are generally understood to be gemstones by jewellers, gemologists and commercially.
With all of this in mind, pearls are subject to the same meticulous, rigorous grading systems as other gemstones.
What about cultured pearls?
Cultured pearls have a historyspanning 600 years. Although they are technically not ‘natural’, in that they are deliberately created by humans, cultured pearls are still organic and totally unique.
Pearl farmers ultimately don’t have control over their pearl production – in fact, only 5% of a pearl harvest will be of the very best quality. Cultured pearls are recognised as real gems in the same manner as natural pearls, and are both graded and sold alongside them.
To an untrained eye, natural and cultured pearls can end up looking the same. As a result, they’re also considered gems by jewellers and gemologists.
Caring for pearls
As we’ve already discussed, pearls are one of the few organic gemstones used in jewellery. But they require a different type of care compared to other mineral gemstones.
Pearls are softer than other gemstones. In fact, you should keep your pearls away from metal and mineral gemstones like diamonds, both of which can scratch these delicate gems. Pearls are also vulnerable toyellowing as a result of dehydration.
Plus, because they’re alkaline, they can suffer from contact with certain acids and alcohol in beauty products. That said, don’t be afraid to wear your pearls – they’ll actually benefit from your skin’s natural oils. Just be sure to avoid perfume, hairspray and fake tan when wearing your pearls, as these can diminish their lustre.
Proper pearl care andstorage can extend the lifespan of your pearl jewellery.
So, is a pearl a gem?
Although pearls have a different origin and mineralogy compared to other gemstones, they are nonetheless gemstones – and very beautiful gemstones at that.
In the case of Natural pearls, these are prized over and above their mineral counterparts, being purely a product of nature, and not being subject to cutting, polishing or any other form of human enhancement - which makes them incredibly rare and therefore expensive.
Classified and recognised by leading institutions as organic gems, pearls are prized for their beauty, rarity, value and cultural importance – just like other gemstones.
If you have questions about whether these distinctive gems would make the right jewellery choice for you,book a consultation with us. As pearl experts since 1989, we’ll help you feel beautifully confident in pearls perfectly matched to your unique features and style.
Plus, we can even createbespoke pearl jewellery, creating a design that tells your story and will be cherished from one generation to the next.
