All the following books are available at huge discounts online and are also available in local libraries
The Book of the Pearl by George Frederick Kunz and Charles Hugh Stevenson
reprint by Dover Books, $17.95 new.
People and Pearls by Ki Hackney & Diana Edkins, Harper Collins 2000, $40.00, new.
The Pearl by Silvia Malaguzzi, Rizzoli Press, 2001 $75.00 new
Pearls: A Natural History by Neil H Landman, Paula Mikkelson, Harry N Abrams 2001 $55.00 new.
The Pearl Book: The Definitive Buying Guide : How to Select, Buy, Care for & Enjoy Pearls
by Antoinette L. Matlins, Gemstone Press 2002, $19.95 new
Pearl Buying Guide: How to Evaluate, Identify and Select Pearls & Pearl Jewelry by Renee Newman, International Jewelry Publications; 2004