The Grading and Valuation of Freshwater Pearls

Posted on Sep 06, 2011 in About Pearls

The grading and valuation of freshwater pearls depends upon the following factors

• Lustre - the greater and more even the lustre the higher the value.
• Smoothness - the smoother the pearl, the more valuable it is – wrinkles and bumps are not necessarily considered to be flaws but add character which does not necessarily detract from the pearl’s appeal
• Size/weight - a freshwater pearl’s size is not as important a price factor as the lustre and surface quality.
• Shape - usually the rounder the pearl the greater its value. Good symmetry can make a pearl more valuable. Most freshwater pearls are baroque in shape which means irregular.
• Blemishes - naturally occurring pitting, discolouration and cavities can decrease the value of freshwater pearls but are usually not as noticeable as those found on seawater pearls because of the irregularity of shape of freshwater pearls.
• Colour - natural colours are white, pink, apricot, yellow, lavender, - some greys and bronzes. Many freshwater pearls are dyed nowadays by the following process. After harvesting, a hole is drilled in the pearls which are then submerged for a period of up to a month in the dye. The dye won’t come off on your skin or clothes because it is absorbed into the cochiolin – the chalky, porous substance which binds with the nacre to form the pearl.
• Nacre thickness - almost all of a freshwater pearl is nacre due to the tissue inserted in the mussel at the start of the culturing process drying up over the 2-3 years cultivation period. With a sea-water pearl, the nucleus is still 60-90% of the pearl, so the thickness and quality of the nacre surrounding it is vital.

Don’t let the price of freshwater pearls, which is significantly lower than seawater pearls, deceive you. Freshwater pearls are just as beautiful in their own way as seawater pearls, it is just that they don’t grow as large nor are they as perfectly shaped as classic seawater pearls – but not everyone wants perfectly shaped creamy classic seawater pearls , do they?