Pearl is a product of oyster. It could be from sea water and fresh water. Its color: white, black, grey- blue, pinkish,  brown.
Pearl is a stone of purity and sincerity.  It enhance fertility and help the birthprocessing. 
It could be used to heal the digestive system, benefit heart and brain funtions.
Chakra: solar, heart, crown.
How care: Not put pear's jewellery near chemical place. 
To clean: using soft milk soap, or clean water.