114 MARINE PRODUCTS OF COMMERCE 



a section between the bars, the entire collar may consist of 2,000 small pearls. 

 Mounting. Many of the pearls mounted as studs or in rings are set upon a 

 peg. This is done to reveal the full size of the pearl; for if it were held in place by 

 claws, part of it would be hidden. The use of a double peg prevents the pearl 

 from turning and thus becoming loosened and falling off the peg. The jeweler must 

 exercise great care in mounting a pearl so that the settings will not scratch or 

 otherwise mar it. 



Cultured Pearls 



The most ingenious development in pearl artifice involved the channeling of 

 these natural processes into mass production methods. The original conception of 

 this industry is attributed to the Chinese. As early as the thirteenth century the 

 Chinese discovered that, by placing an object such as a small image of Buddha 

 in a living fresh-water mussel and returning the organism to its natural environ- 

 ment, a deposit of nacre was slowly built up around the nucleus. It was not until 

 1890 that present day commercialization of the Chinese discovery was begun. 



There have been several attempts in recent years to culture fresh-water pearls 

 in the United States. One cultvirist undertook the work in the San Saba River, 

 Texas. Although several fresh-water cultured pearls were grown, the enterprise 

 failed. Spherical glass beads were used as irritants instead of the usual mother- 

 of-pearl cores. 



The founder of the Japanese cultured pearl industry was Kokichi Mikimoto. 

 After much discouragement he succeeded in producing blister or baroque pearls 

 about 1894. Some 15 years elapsed before he successfully produced a wholly 

 spherical pearl. The Japanese process consists (according to Japanese published 

 accounts released by the firm of Mikimoto) of removing from a living oyster the 

 mantle parenchyma which is used as a bag to envelop the nucleus of the pearl. 

 When this nucleus, which consists of a fragment of fresh-water mussel, has 

 been inserted into the bag, its mouth is secured with a cord and the whole is 

 introduced through a surgically made opening into the subcutaneous tissue of the 

 shell-secreting epidermis of another oyster. In the same operation the cord is 

 withdrawn, the wound made by the lancet disinfected, and the oyster, having 

 been returned to the sea, left to cover the nucleus with as many layers of nacre 

 as necessary to produce perfectly spherical pearls. 



Since publication of these data there has been considerable advancement in the 

 technique of growing cultured pearls. It was found, for example, that it was un- 

 necessary to make a "surgical" operation on the pearl oyster; instead, one or 

 more mother-of-pearl beads may be inserted into the mantle parenchyma to 

 start the process of calcium carbonate deposition around the nucleus or irritant. 

 In short the whole enterprise is now one of mass production. Of the total number 

 of pearl oysters "set", it is believed that only 60 per cent will produce cultured 

 pearls of salable value. A much lower percentage of this total will yield fine, 

 flawless pearls. 



Prior to World War II Japanese pearl culturists carried on their work, not only 

 in the waters surrounding Japan, but around the island of Palau in the South 

 Seas. By using the large Australian type shell cultured pearls up to % of an inch 

 could be grown in that region. 



Certain salient facts about Japanese cultured pearls are imknown. Through 



