Although Susannah works exclusively with cultured pearls, there are various categories and pearl types:
- Natural Pearls - These are extremely rare and form when a grain of sand or other particle enters an oyster shell. As their name implies, the process of coating the particle in a crystalline substance (called nacre) is completely natural. However, only a tiny proportion of oysters produce gem quality pearls - perhaps one in 10,000 - and then it has to be found deep in the ocean!
- Cultured Pearls - With these, man lends nature a helping hand by introducing the particle (sometimes called the nucleus) into the shell. After that, nature takes over to cultivate the pearls either in saltwater or in freshwater (1-4 years).
- Cultured Saltwater Pearls - originally developed by Mikimoto in Japan. Pearls are cultured in the akoya oyster shell in seawater. This is an intensive form of culturing where a small bead nucleus is inserted into the oyster with a small piece of grafted mantle that stimulates the nacre pearl coating with pearls growing to a maximum of 10mm. Generally only one pearl is cultivated at a time and round pearls with a good lustre tend to form over a period of approx 2 years.
- Cultured Freshwater Pearls - This type of culturing has been revolutionised over the past 15 years. Pearls are cultured in a larger American mussel shells that can accommodate many more pearls than the akoya oyster shell. Small slits are made on the inside of the mussel shell and mantle inserted from another mollusk which stimulates the growth of all nacre pearls with no nucleus giving an excellent lustre and interesting shapes with sizes up to 14mm.
- South Sea Cultured Pearls - these pearls are cultured in large Pinctata Maxima shells in unpolluted regions of the world such as the seas around Western Australia, Burma and Tahiti. Australia produces large excellent quality south sea pearls around Broome on the North West Coast often up to 20mm.in size. Tahiti also produces beautiful large South sea grey pearls from the black lip oyster
- Imitation Pearls - Again as their name implies, imitation pearls are manufactured rather than cultivated. To the untrained eye, many imitation pearls such as “Mallorcan Pearls” (made up from a mixture of fish scales) look like the real thing, but on closer inspection there's no substitute for natural lustre.
What to look for
The aesthetic value, and so the price, is affected by the following:
- Surface - While minor imperfections are natural, and to be expected, extensive blemishes and pit marks will reduce the pearl's value. So, the smoother the better.
- Colour - There is a wide range of colours that occur naturally - pinks, whites, creams, even black. However, many cultured pearls are dyed to suit fashion requirements.
- Size - Although the larger the size, the higher the value is a good general rule, price is also affected by the quality of the pearl and its cultivation (whether fresh or saltwater).
- Lustre - This is the most important aspect, and relates to how brightly the pearl shines. A low lustre pearl appears chalky, whereas a high lustre one reflects light well.
Caring for Pearls
Wipe your pearls with a damp cloth after wear to remove oil or chemicals that can damage their lustre.
- Keep your pearls in a separate soft pouch, so they are not in contact with other jewellery that may scratch them.
- Pearls should be restrung when needed or approximately every 2 or 3 years depending upon how often they are worn. Knots between the pearls protects them from rubbing against each other.
- Be very careful not to spray pearls with scent or hairspray.
- Do not wear pearls when swimming - Chlorine will seriously damage their nacre and stringing will be weakened by water (remember this applies to earrings as well as necklaces)
© Susannah Chenevix-Trench