A Guide to Pearls
Pearls are a key essential in every girl’s jewellery box. Pearls are created when a mollusc secretes nacre. Nacre is deposit layers of crystalline carbonate held together with an organic compound called conchiolin which gives each pearl its uniqueness, value and beauty. As the thickness of the nacre increases so does the quality and durability of the pearl. Did you know that pearl is the birthstone for June and that pearls are traditionally given to mark a 30th wedding anniversary?
Natural and Cultured Pearls
Natural pearls are formed when an intruder enters the mollusc and continuous layers of nacre grow like little onion skins around the particle. Natural pearls have always been considered rare and can be very expensive. Cultured pearls also grow inside of a mollusc but with a little help. The shell is opened carefully and an object is inserted depending on the final shape of pearl desired. Over time the object inserted is coated with layers of nacre. The depth of the nacre coating depends on the type of mollusc involved, the water it lives in and how long the intruder is left in place before being harvested.
- Spherical Pearls – these are round and typically the most desirable, the rounder a pearl the more expensive it typically is.
- Symmetrical Pearls – these are pearls which have symmetry from one side to the other but are not round such as pear shapes.
- Baroque Pearls - these are irregularly shaped pearls and are often the least expensive category of pearls however can be unique and quite beautiful.
Types of Pearls
Here at Sheenashona Jewellery our pearl necklaces, pendants, bracelets and earrings feature Freshwater, Akoya and Tahitian Pearls. Our pearls are only ever designed and set in precious metals which include sterling silver or 9ct and 18ct yellow or white gold.
About Freshwater Pearls
Naturally freshwater pearls have been around for thousands of years whilst cultured freshwater pearls came onto the market in the 1970s. Over the last 40 years as skills have been honed, todays freshwater pearls are lustrous and rounder than their predecessors and certainly on par with their saltwater cousins.
Rather than growing in the sea like the Akoya and Tahitian pearls, freshwater pearl mussels grow in lakes, rivers, ponds and reservoirs, hence their name. Freshwater pearls are much easier to grow than saltwater pearls and you can grow up to forty pearls at a time with a 95% yield in comparison to saltwater pearls that typically grow one or two pearls with a 15% yield. As a result this tends to make freshwater pearls more affordable but no less desirable or beautiful. In addition freshwater pearls are also nucleated differently than saltwater pearls. A saltwater pearl farmer will implant a bead and a small square of soft tissue from a donor oyster, this soft tissue then grows around the bead and lays nacre onto it forming a pearl. A freshwater pearl farmer only introduces the soft tissue which means that freshwater pearl are 100% nacre.
Freshwater pearls come in a beautiful range of white, peach, pink and purple colours and have a soft lustre, often described as giving them an inner glow. A good sized freshwater pearl is about 6-7mm in diameter although they are farmed up to 11-12mm. Freshwater pearls are produced in Africa, India, Japan and the Mississippi USA. The best quality freshwater pearls however are still said to come from South Eastern China.
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About Akoya Pearls
Known as the original cultured pearl, the Japanese were the first to discover how to culture pearls with their native pearl growing oyster, the saltwater Pinctada fucata at the beginning of the 20th century. Cultivation starts by implanting a perfectly rounded mother-of-pearl nucleus along with an irritant into the oyster. Relatively small oysters, the Akoya pearl is rarely bigger than 9mm but because they’re bead nucleated, they are generally bigger than 4mm in diameter. Due to its size, the Akoya pearls oyster tends only to produce one pearl at time however they can produce up to three at once but that’s rare. Akoya pearl producing mussels also tend only to be nucleated once.
As with each pearl type, Akoya pearls have their own characteristics. Typically they have a beautiful array of white, blue, grey and yellow hue with a distinctive mirror-like lustre. Freshwater pearls tend to have a soft glow whilst Akoya Pearls tend to have the most brilliant shine. Akoya pearls are typically the roundest of pearls and the rounder a pearl is, the more expensive it tends to be.
For many years, Akoya pearls were only grown in Japan, but now you’ll find Akoya pearls from South East Asian ountries such as China, Thailand, Vietnam and Burma. It is however widely acknowledged that some of the best quality Akoya pearls still come from Japan.
About Tahitian Pearls
Tahitian pearls came onto the market in the mid-1970s. The industry at that point in time had become accustomed to the light colours of Akoya pearl therefore there was a lot of doubt initially over these huge dark coloured pearls. It was only once they were tested by the GIA (The Gemological Institute of America, one of the world's foremost authority on diamonds, coloured stones, and pearls) that the jewellery industry accept their authenticity.
The Tahitian pearl oyster, Pinctada margaritifera, is native to French Polynesia, the capital of which is of course Tahiti. Tahitian pearl cultivation allows one nucleus per mussel. Grown in huge black lipped oyster, the smallest Tahitian pearls you tend to find are 7mm in diameter but can grow up to 20mm. Tahitian pearls are typically grown in unspoilt islands miles away from civilisation as oysters are very sensitive to pollution. Today however Tahitian pearls are also cultivated in Indonesia, South East Asian countries including Thailand and Burma as well as the Gulf of Mexico.
Tahitian pearls have the most wonderful shine along with incredible combinations of colours from peacock to pistachio, green to silver, orange to blue and yellow. Tahitian pearls are so luxurious and one of our favourites here at Sheenashona Jewellery. It is for this reason that you will find some beautiful Tahitian Pearls set in 18ct white in our Kensington Pearl Collection.
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