Nucleated pearls are pearls grown around a solid nucleus, rather than a piece of mantle tissue from a mollusc. The nucleus is likely to be a whole freshwater pearl, or (particularly for unusual shapes) can be made of mother-of-pearl. This can be any shape and, within reason, up to about 16mm. Nucleated pearls can be perfectly round, if the nucleus is spherical, which makes them quite valuable, especially in the larger sizes. This is not only true of the epitome of nucleated pearls, the Akoya (please see my Akoya guide for more details), but also of nucleated freshwater pearls, which can reach sizes of around 15/16mm.
To create various pearl shapes, from the cross to the 'chinese number' shape and many in between, the Chinese have discovered that 'the mussel is their oyster'. This wonderful creature just produces whatever man tells it to, by covering the nucleus implanted into the mussel with nacre. There is a huge tablet nucleated pearl, with dripping sides, reminiscent of Dali's painting of watches. There are simple coin pearls, double coin pearls, twisted pearls, all manner of gorgeous shapes and sizes.
Original Lake Kasumi pearls are a rare find these days, due to pollution of the main growing Lake Kasumi-ga-ura. The same thing happened to Lake Biwa-ko in the 1980s (more info on this in the guide to Unusual pearls). All is not lost, as the Chinese now have a hybrid mussel, which is producing the Chinese equivalent of the Japanese Kasumi pearl. These are walnut-shaped, like the original, with a bumpy skin and stunning lustre. It is quite difficult to tell them apart from the originals. Some of the Chinese ones have a slight tail, a bit like the flameball pearl.
Flameball pearls grow to huge sizes and come in amazing shapes and colours. They are easily recognised when they have a tail, like a comet, after which they were named. They can, however, come in the most amazing baroque shapes and colours, including bi-colours. These are unusual, expensive and sought-after pearls.
forthgirl at Culross Creations..... for my shop see http://stores.ebay.co.uk/Culross-Creations/Akoya-pearls
My Akoya pearl guide can be found at:- http://reviews.ebay.co.uk/About-Akoya-pearls?ugid=10000000176473258
My Freshwater pearl guide can be found at :- http://reviews.ebay.co.uk/Pearls-Freshwater?ugid=10000000176617237
My Keshi and Unusual Pearls guide can be found at :- http://reviews.ebay.co.uk/Pearls-Unusual-and-Keshi?ugid=10000000176617141
My South Sea and Tahitian pearls guide can be found at :- http://reviews.ebay.co.uk/Flameball-and-Nucleated-Pearls?ugid=10000000176616995