18KGP and 23KGP are the symbols of alloy imitation jewelry. To put it simply, GP is the symbol of gold-plated or gold-plated jewelry, and the front 18K or 23K refers to the gold content of the gold-plated layer outside it. Some people may ask at this point, but most of the jewelry of 18KGP and 23KGP is white instead of yellow. This is the confusion between pure gold and k gold. One of the characteristics of pure gold is softness, so it is easy to fall off when inlaid with gems because of insufficient strength. Therefore, people add silver, copper, zinc and other metals to gold to increase its strength and toughness. The gold ornaments made in this way are also called K gold. In jewelry inlaying, almost all gems are inlaid with K gold with different K numbers. This not only achieves the nobility of gold, but also makes up for its shortcomings, and can be made into various colors as needed. K-gold jewelry popular in the world has various colors, and the common ones are yellow and white. K gold is divided into colored gold alloy and platinum alloy according to color. Au-Ag-Cu(-Zn) alloy is the most commonly used colored gold alloy in ornaments. Platinum alloys are mostly Au-Ag-Ni(Cu, Zn) and Au-Ag-Pd(-Zn, Cu) alloys. Gold mixed with 25% palladium or nickel and zinc. , will turn white, its main component is gold. This name is platinum, commonly known as K gold. (Note that platinum and platinum are not the same concept. Many profiteers play word games to deceive consumers, and some take advantage of people's misunderstanding and lie that platinum is the common name of platinum. ) 18KGP refers to gold-plated or gold-plated jewelry with a gold-plated layer of 18K gold.