The gold alloy can create several different gold colors. White gold is a result of adding palladium to gold; pink gold is an alloy of silver, copper, palladium, and sometimes other metals. Among precious metal professionals, it is well-known that the key to form purple gold is to compound aluminum with gold. However, it has issues with processing and discoloration. To solve the technology problem, the Cierin team collaborated with three universities in the research and development of purple gold. As a result, they succeeded in exploiting the perfect purple gold for jewelry, coated with nanocoating, which prevents discoloration and keeps the long-lasting, lustrous purple color. Cierin is a jewelry collection of each piece with a tint of purple, which reminds us of the image of noble and elegance.