GP is the abbreviation of English goldplain, commonly known as forging gold in business. This logo means that the product is mainly made of phosphorus and copper in general metals after high-temperature forging, and then plated with a layer of gold, which can be divided into two types according to the thickness of the gold layer. The thickness of gold-plated layer is about 1mi (mic is the unit of gold-plated layer thickness stipulated by international standards), and the gold-plated layer is about 3mi.

Simply put, GP is the symbol of gold-plated or gold-plated jewelry, and the front 18K refers to the gold content of the gold-plated layer outside it. At this point, some people may ask, but most of the jewelry of 18KGP 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. )