Pearl is a born beauty, always keep that loveliness and charm which God gave her. However, with some treatments and improvement, she can turn to be more desirable and attractive.
Pearls processing technology Preliminary treatment: Soaking pearls in mixed liquor of ammonia and benzoylate so as to loosen the texture, and take pure glycerin as dehydrating agent to remove the water inside the pearls.
Bleaching: With an average temperature from 20-30 degrees Celsius, the pearls are placed in Hydrogen peroxide, which is at concentration of 5% and ph7-8. Exposing them to sunlight or ultraviolet radiation for 7-10 days, the pearls will change to off white, silver or pure white. The bleaching is actually an old-aged pearl processing method and is used wildly by pearl dealers in the world.
Dyeing: The pearls are immersed for a period of several days in diluted special chemical solutions and heated under an average temperature from 40-50 degrees Celsius. Blue, green, red, purple, black, silver and brown hues all can be dyed. It needs few weeks for coloring agent to intrude into pearls. Temperature, light source and pearl structures all determine the resulting colors.
Polishing: Polishing is one of important processing skills and is needed after bleaching. It increases the bleaching effect greatly. Tiny pieces of walnut shell, bamboo chips, wax, diatomite and salt particle are crucial materials for polishing.
Others: γ-ray radiation is a reliable and safe processing method of changing pearls colors. Peeling is another processing method for getting of the surface defects. Due to the difficulty in manual operation, it is not used often nowadays.
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