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All About Pearls

Unlike other gemstones which are minerals, pearls are organic and are formed by living organisms.  Pearls are formed in the soft layer of mollusks.  Examples of mollusks are oysters and mussels.  Pearls are composed of organic conchiolin and calcium carbonate building up as concentric layers secreted by their host.

Currently mostly all pearls found on the market today are cultured pearls.  This is done by placing an object known as a nucleus within the oyster or mussel.  This causes the organism to grow a pearl around the nucleus.  Oysters are cultured and harvested in large numbers for the purpose of growing pearls within them. 

Pearls come in a variety of colours, but the most popular saltwater pearls are known as Akoya Pearls.  Akoya Pearls originate from Japan and China.  Akoya Pearls occur naturally in white, and are sometimes treated to look black or a very dark blue.  To distinguish an Akoya Pearl from the other types is from its round shape and mirror like metallic luster.  Most of the small type Akoya Pearls are from China and the large types are from Japan. 

White South Sea Pearls and Golden South Sea Pearls are categorized as exotic pearls.  White South Sea Pearls usually originate from the western coast of Australia.  Golden South Sea Pearls originate from the Philippines and Indonesia.  Tahitian Pears are also another popular variety of saltwater pearls.  Tahitian Pearls come from Tahiti in the Pacific Ocean and other French Polynesia.  They range in colour from green to blue, red, gold and black.

The most abundant form of Pearls is freshwater pearls.  Freshwater Pearls come from mussels and each mussel produces 50 pearls.   They are less desirable to their salt water counterparts because of their irregular potato like shape.  However advancement in culturing freshwater pearls has greatly improved on this flaw.  Generally no freshwater pearl will be perfectly rounded because it is nucleated with small pieces of tissue, as opposed to round beads.  Freshwater pearls are most distinct because they naturally occur in a variety of colours such as pink, purple, peach, white, occasionally in periwinkle blue. 

Natural pearls are almost always used in single-Pearl jewelry pieces.  Natural pearls are expensive due to their rare occurrence.  Antique Pearl jewelry can also be very valuable due the fact that the Pearls are natural. 

Pearls are most valuable when in perfect round shape.  Other significant factors include luster, colour, surface quality, size, and nacre thickness.  If the pearls are strung on a strand, they need to be expertly matched so that the Pearls look consistent.  Many of the freely shaped pearls are used for pendants or rings that accentuate the unique shape. 

The percentage of blemishing is a good indicator of quality.  Highest quality pearls should be 95-99% blemish free.  There is no such thing as a “perfect” pearl and buyers should not expect to find one.

Pearls have an overtone.  The overtone describes the glint of a pearl in various lighting and is most noticeable in salt water pearls.  White Akoya Pearls will have overtone in rose, cream, and silver. Tahitian Pearls have overtone in almost every colour.  Golden South Sea Pearls will have gold body colour with silver, green or rose overtones.  White south sea pearls, have overtones in silver, rose and ivory.  Generally  a combination of rose and silver is the most sought after overtone in white pearls. 

Variety of Pearls

There is literally hundreds of variety of pearls.  Here is a list of the most commonly known pearls. 

  • Abalone Pearl
  • Akoya Pearl
  • Black Pearl
  • Cortez Pearl
  • Cultured Pearl
  • Freshwater Pearl
  • Keshi Pearl
  • Mabe Pearl
  • Melo Pearl
  • Natural Pearl
  • Oriental Pearl
  • Saltwater Pearl
  • Scallop Pearl
  • South Sea Pearl
  • Tahitian Pearl

Treatments and Enhancements of Pearls

Almost all Pearls found today are Cultured Pearls.  The gem industry treats this as normal business practice.  Natural and cultured pearls can be distinguished using X-ray equipment which can examine the nucleus of a pearl. 

Pearls are dyed to give them a more valuable color and increase their overtone.  They are most commonly dyed black and blue