PEARLS AND THE PEARL INDUSTRY 121 



The imitation pearl business is very large; in 1948 one company alone made 

 5 billion plastic cores for imitation pearls. During the decade 1939 to 1949 the 

 amount of pearl essence used in making imitation pearls in the United States 

 increased from about 10,000 pounds to approximately 20,000 pounds. 



Hollow Class Beads. The hollow glass beads used in making imitation pearls are 

 of two types. The cheaper ones are made by blowing thin glass tubing into a 

 mold, resulting in a number of connecting bulbs which are cut apart after the 

 glass cools. These beads are coated inside with a suspension of pearl essence in 

 gelatin solution. When this is dry, the beads are filled with paraflBn or other wax. 

 Such beads are light and will usually float on water. Sometimes barium sulfate is 

 added to the wax to make them heavier and whiter. 



The better grade of hollow beads is made of specially selected, soft, colorless 

 glass tubing. The tubing is sealed at one end with a blowtorch and a bulb of the 

 desired shape and size is blown. A sheet metal mask, with a hole slightly larger 

 than the hole desired in the bead, is pressed against the end of the bulb or bead, 

 and a small pointed flame is directed against the hole. A hole is blown through 

 the glass and the edges retracted and smoothed by brief contact with the flame. 

 The bead is then cut away from the glass tube. The hole at the cut end is also 

 smoothed in the flame with the help of the mask. After these beads have been 

 coated inside with a pearl essence suspension in gelatin solution or in a lacquer, 

 they are filled with wax or wax containing barium sulfate. 



Solid or "Indestructible" Imitation Pearls. Solid beads made of opal glass are 

 often used for the "indestructible" type of imitation pearls. The exact degree of 

 opalescence affects the appearance of the finished bead and is varied in practice 

 to give the desired tint. The beads are made from glass tubing, having a capillary 

 bore of the right size for stringing. The tubing is cut into short lengths and strung 

 on a small iron or copper wire so that these pieces are held in a gas flame and 

 rotated until the desired globular shape is attained. Then they are removed from 

 the flame and rotated untfl cool. 



Another method of making beads, used on a large scale, is to tumble the short 

 lengths of tubing into a mixture of fireclay and graphite until the holes are 

 plugged. They are next placed in an iron drum containing powdered talc which 

 prevents them from sticking together. The drum is slowly revolved while it is 

 heated hot enough to soften the glass and the pieces slowly assume the desired 

 globular shape. They are revolved slowly as they are cooled. After they have been 

 cleaned and the clay-graphite mixture removed from the holes, the beads are 

 ready for coating. 



Alabaster Beads. Many of the best imitation pearls are made from alabaster 

 beads (Roberts 1949) which are usually handmade. A drop of molten alabaster 

 on a wire is spun in a flame until a smooth, round bead is obtained. After cooling, 

 the wire is dissolved in acid, leaving a hole in the center of the bead for stringing. 

 The resultant bead is translucent and makes a beautiful imitation pearl. 



Dipping the Beads. In making imitation pearls the opal glass, alabaster, or 

 plastic beads are coated with a lacquer containing lustrous guanin crystals in 

 suspension. One commonly used lacquer comprises 50 gm of guanin crystals, 

 35 gm of 20-30 nitrocellulose, and 369 gm of amyl acetate per pound; 4 to 10 

 coats of this are applied to the bead. To prepare such a lacquer it is only necessary 

 to dissolve nitrocellulose in a suspension of pearl essence in amyl acetate. If 



