June Birthstone – Pearl
June has three birthstones, ranging from creamy-coloured opalescent Pearl and Moonstone to the rare colour-changing Alexandrite – which is one of the most valuable gems on earth. With this spectrum of price points and colour options, people with June birthdays can choose a beautiful gemstone to fit any mood or budget. So today we’re going to look at the Pearl.
Pearls are the only gemstones made by living creatures. Mollusks produce pearls by depositing layers of calcium carbonate around microscopic irritants that get lodged in their shells – usually not a grain of sand, as commonly believed. While any shelled mollusk can technically make a pearl, only two groups of bivalve mollusks (or clams) use mother-of-pearl to create the iridescent “nacreous” pearls that are valued in jewellery.
Appropriately, the name “pearl” comes from the Old French perle, from the Latin perna meaning “leg,” referencing the leg-of-mutton shape of an open mollusk shell. Because perfectly round, smooth natural pearls are so uncommon, the word “pearl” can refer to anything rare and valuable.
The rarest, and therefore most expensive, pearls are natural pearls made in the wild. The majority of pearls sold today are cultured or farmed by implanting a grafted piece of shell (and sometimes a round bead) into pearl oysters or freshwater pearl mussels.
Pearls are very soft, ranging between 2.5 and 4.5 on the Mohs scale. They are sensitive to extreme heat and acidity; in fact, calcium carbonate is so susceptible to acid that pearls will dissolve in vinegar.
The finest pearls have a reflective lustre, making them appear creamy white with an iridescent sheen that casts many colourful hues.
Cultured freshwater pearls can also be dyed yellow, green, blue, brown, pink, purple or black. Black pearls – which are mostly cultured because they are so rare in nature—aren’t actually black but rather green, purple, blue or silver.
Pearls used to be found in many parts of the world, but natural pearling is now confined to the Persian Gulf waters near Bahrain. Australia owns one of the world’s last remaining pearl diving fleets, and still harvests natural pearls from the Indian Ocean. Today, most freshwater cultured pearls come from China. South Sea pearls are cultured along the northwestern coastline of Australia, the Philippines and Indonesia.
How to Buy Pearls
If you’re shopping for perfectly round natural pearls, you’ll need patience and a large budget. Most pearls on the market today are produced through culturing, giving pearl buyers a wealth of options.
Most freshwater cultured pearls are made in China, while common saltwater cultured pearls include Akoya, white or golden South Sea, and black Tahitian. Pearls are one of few gems not measured by carats. Lustre is the most important aspect of choosing a pearl. The finest pearls are metallic and reflective like mirrors.
Pearls can range in size from 3mm to 13mm. Because pearls do not require polishing or faceting finding a pair of pearls that match perfectly in size, colour and lustre can be more difficult—and more expensive. A matched strand of natural pearls may sell for hundreds of thousands (if not millions) of Rands.
Beware imitation pearls or shell pearls, which are made from conch shells or glass coated with a solution containing fish scales. Rubbing two pearls together will reveal if they are smooth imitation stones, or if they feel gritty from the nacre that comprises natural and cultured pearls. The nature and number of blemishes or irregularities on the pearl. As products of nature, few pearls are completely blemish free. The thickness and regularity of the nacre. For nacre quality to be acceptable on a bead-nucleated cultured pearl, no evidence of the bead should be visible and there should be no chalkiness.
You should also know that cultured pearls routinely undergo treatment to improve their appearance. Some may be colour enhanced by heating, dyeing, irradiation and coating. Gem experts can distinguish natural pearls from cultured pearls by using gemological X-ray equipment. Natural pearls consist entirely of concentric growth rings, while cultured pearls have a solid nucleus of the bead or shell that was implanted to stimulate pearl production.
Care and Cleaning
Pearls are a comparatively soft gem and require special care. Store them separately from other gemstones and metal jewellery to prevent scratching. Never store pearls in a plastic bag — plastic can emit a chemical that will damage their surface. Always apply perfume, hair products and cosmetics before putting on your pearl jewellery. The best way to clean your June birthstone: Use a soft, damp cloth, ideally after each time they are worn.