Pearl, freshwater

MFA Acc. #: 2006.101

Description

Marsh-bird brooch
MFA# 2007.827

Pearls obtained from mussels in freshwater lakes and rivers around the world. Freshwater pearls are cultivated in Lake Biwa (Biwa Pearls) in southern Japan and in China (China Pearls, Rice Pearls). Freshwater pearls have irregular shapes and come in a variety of nonwhite colors. They are often dyed. The surface of Rice pearls is generally rough and the surface of Biwa pearls is usually smooth.

Synonyms and Related Terms

freshwater pearl; fresh-water pearl; Biwa Pearls; China Pearls; Rice Pearls

Physical and Chemical Properties

• Mohs Hardness = 3 - 4
• Density = 2.68
• Refractive Index = 1.57

Resources and Citations

• Grading chart for freshwater pearls: Pure Pearls

• Oppi Untracht, Jewelry Concepts and Technology, Doubleday & Co., Inc., New York City, 1985