gems, pearl, Ceylon, Sri Lanka, Gulf of Manaar, Persian Gulf, South Seas

Dall provides a general account of pearls and pearl fisheries, discussing the mollusks that produce pearls, the manner in which pearls are formed, their varieties and characteristics, and the principal fisheries known at the time. He considers both marine and freshwater pearl-producing mollusks and describes important producing regions, methods of fishing and collecting, and aspects of the pearl trade. Attention is also given to the causes of pearl formation, differences in color, form, and quality, and the occurrence of pearls in mollusks other than the principal commercial pearl oysters. The paper offers a useful late nineteenth-century synthesis of contemporary zoological and commercial knowledge of pearls and their fisheries.