138 MARINE PRODUCTS OF COMMERCE 



and are thus exported indirectly. Italian cameos are exported to many different 

 countries, among which the United States and the United Kingdom have tradi- 

 tionally been of primary importance. 



Jewelry and Miscellaneous Objects 



Mother-of-pearl finds use in the manufacture and ornamentation of a great 

 variety of objects for household and personal adornment. Many of the very finest 

 grades are made into knife handles, opera glasses, umbrellas, etc. It is often used 

 for the decoration of fountain pens, clocks, ink wells, picture frames, and other 

 valuable things. Jewelers use it for the manufacture of belt buckles, combs, bar 

 pins, beads, studs, cuff links, hat pins, etc. The pearl obtained from abalones is a 

 favorite. 



Mother-of-pearl is sometimes employed to produce a coarse variety of mosaic, 

 called nacre chinois in France. It imparts an iridescent sheen to metal surfaces and 

 is used in Naples for iron bedsteads. The design, having been drawn in varnish 

 on the iron, the iridescence is imparted by attaching, with the same varnish that 

 is used to render the design brilliant, very thin layers of mother-of-pearl. In 

 Japan similar, but more carefully executed, work is done on lacquer and the in- 

 terior surface is lined with layers of pearl or coatings of pearl powder, forming 

 designs of flowers, fruits, etc. 



In India the chank shell is held sacred by the Hindus and is utilized in a great 

 number of curious ways. In Bengal every married woman of all thoroughly 

 Hinduized castes possesses a pair of chank bangles (bracelets) lacquered in 

 vermilion as a visible token of her married state. In many other parts of India 

 chank bangles are worn to designate the caste to which the wearer belongs. 

 Chanks are used in many religious ceremonies, including marriage and death 

 rites, and also medicinally for the treatment of a number of diseases. 



Preservation 



Mother-of-pearl beads and other objects sometimes become soiled or lose their 

 luster. In many cases they may be cleaned by the use of a soapy warm water 

 solution to which a few drops of ammonia have been added. If, however, the 

 beads become stained, they can scarcely be restored; but, if they have merely 

 become roughened, or have lost their lustre, they may be repolished with a paste 

 of dilute sulfuric acid * the polishing being done with a circular felt buffer or a 

 hand buff. If the beads are strung when the ammonia water is applied, each bead 

 should be wiped off with a bit of chamois or tissue paper that has been dipped 

 in the cleansing solution. If, however, they have not been cleaned for a long 

 time, a regular crust may have formed over them. As much as possible of this 

 should be carefully scraped oflF before the ammonia water is applied. 



Blister Pearls 

 Origin 



The term "blister pearls" is used for those which develop on the shell of the 

 pearl oyster. They owe their origin to the defensive or protective action of the 

 moUusk in resisting the intrusion of some animal, such as, for instance, a boring 



* Caution: Never try to clean gem pearls with these solutions. Use only C.P. grade 

 carbon tetrachloride and wipe dry with a soft cloth. 



