“Tahiti” is considered in the trade to be quite well versed in Pearls. Although he could share his own thoughts and ideas about pearls in this section, “Tahiti” feels there are entire websites, trade oversight organizations and the pearl producers themselves who can provide the information clearly and from several different perspectives. He feels this will allow you a better, well-rounded perspective of the information and prevailing views concerning pearls. The following links should make your journey through the world of pearls fascinating, informative, fun and exciting. Happy Learning!

What are the main pearl categories or types?

General Information: http://www.cpaa.org/about.asp
Tahitian Cultured Pearls: http://www.perlesdetahiti.net/site/en/a-pearl-is-born.html
South Sea Pearls: http://www.sspc.net/eng/southseapearls001.htm
Japanese Akoya Pearls: http://www.pearl-guide.com/akoya-pearls.shtml
Chinese Freshwater Pearls:  http://www.pearl-guide.com/freshwater-pearls.shtml

What is the difference between “Natural” and “Cultured” Pearls?

http://www.gia.edu/research-resources/library/featured-gemstones/pearl-and-cultured-pearl

How are pearls formed or Cultured?

General information: http://www.cpaa.org/how.asp
Tahitian Cultured Pearls: http://www.perlesdetahiti.net/site/en/29.html
South Sea Pearls: http://www.sspc.net/eng/southseapearls002.htm

What are the characteristics that help determine a pearls quality and value?

General information: http://www.cpaa.org/valuation.asp
Tahitian Cultured Pearls: http://www.perlesdetahiti.net/site/en/499.html
South Sea Pearls: http://www.sspc.net/eng/southseapearls003.htm

Some thoughts on current pearl grading.

http://www.pearl-guide.com/pearl-grading.shtml
In pearl producing countries such as French Polynesia and Australia, the A-D system is nearly universally used. However, when the pearls are auctioned in Hong Kong, these same producers utilize the A-AAA system when selling to wholesalers. These producers include the largest  Tahitian Cultured Pearl producer in the world, the Robert Wan organization, and Paspaley Pearl, one of the oldest, largest South Sea pearl producers in the world. As these two companies are the fathers of the industry and they use both systems, nobody, absolutely nobody, can honestly say one system is correct and the other is not.

Also see the following links:

"Mikimoto" knows how to grade pearls, correctly.

Online Pearl Jewelry Retailers and their dubious approach to representing and grading pearls.

How to be more successful selling pearls- a great article