Precious metal material

Platinum is a rare and expensive natural pure white metal. It is one of the rarest precious metals used in jewelry in the world. Its annual supply is only 5% of that of gold. It has almost twice the strength of gold and is 30 times rarer than gold. Platinum has a pure white luster and is naturally pure, with a purity of over 90%. It is naturally formed and will not fade even with frequent wear. Pt900 indicates platinum jewelry with a purity of 90%, and Pt950 indicates platinum jewelry with a purity of 95%.

(2) K Gold K gold refers to an alloy made by mixing gold with other metals. As its English name is Karat Gold, it is simply called K gold. For the precious metals section, pure gold is 24K. However, pure gold is too soft to be suitable for making watches and must be mixed with other metals to enhance its hardness. Generally, silver, copper and palladium are the main metals used. But no matter which metal is mixed, the proportion of pure gold always accounts for 75%. With the proportion of gold, silver and copper varying, five different colored materials can be produced, each represented by N to indicate the copper content. For instance, red gold, which has the highest copper content, is denoted as 5N, while the correct term for white gold is white K gold.

(3) Half gold

The combination of stainless steel and 18K gold materials presents a unique two-color aesthetic.

(4) Gold-plated: The case is made of stainless steel and coated with a layer of gold alloy. It is formed into a whole by mechanical rolling. Its thickness is measured in micrometers, with 1 micrometer equal to 1/1000 of a millimeter. It is at most 10 to 15 microns thick, while generally only 2 to 3 microns thick.

(5) Electroplating (gold plating, which should be classified under the attribute of precious metals, will be explained below) Electroplating is a common method for decorating the case of modern watches. Electroplating technology emerged in the 1970s. Due to its uniform and firm appearance, lower cost than gold plating and less likelihood of peeling off, as well as the absence of the possibility of yellowing, discoloration and rusting of forged cases, both were quickly phased out of the market.

(6) In terms of the purity of silver, 925 is not the highest purity of silver! You can check the domestic real-time silver prices, which have three trading purities: 99.99%, 99.95%, and 99.90%. All of these three are too soft to be used for jewelry. Generally, 92.5% is the most suitable for jewelry (such as hardness and ductility), so 925 can also be called pure silver. But it's not really pure silver. Silver is an ancient precious metal and was the most commonly used material for pocket watches in the 18th century and before. 925 represents the purity of silver and is the highest purity of silver (not the highest purity, the common ones are 925- suitable for jewelry, 975- suitable for tableware, 990, and even purer ones - court note). Silver is an active metal that readily undergoes chemical reactions with sulfur in the air, forming a black oxide layer that turns silverware black. Nowadays, it is far inferior to gold in watch applications because it is extremely prone to losing its luster due to water, moisture and other reasons.