What does the letter k behind the golden characters in Lao Fengxiang mean?

Pure gold refers to 24K gold, which means that its gold content is 100 %. The highest is 24K.

The pure gold content in gold is called "gold position", English is karat, so it is called K gold. Generally, pure gold is 24K, that is, the theoretical gold content is 100%. Therefore, 1K means that the amount of gold contains pure gold accounts for 1/24, about 4.16%. There are generally many in my country that use 18K to inlaid jewelry, so that the inlaid jewelry is relatively high. K gold refers to the alloy mixed with gold and other metals. Karat is the measurement unit of K gold. It is divided into 24 copies of pure gold. According to the gold content in jewelry, it is divided into different K gold, so 24K refers to pure gold. For example, 18K gold content is 18/24 = 75.0%, and because 18K gold content is 75.0%, it is also called 750.
The differences and ingredients of the main K gold:
(1) Yellow K gold jewelry (18k)
yellow K gold jewelry (referred to as yellow K gold), which is the alloy of gold and other precious metals, According to the gold content, it can be made into different K gold series jewelry. For example, 18K gold (750 yellow K gold) refers to accessories containing 75%pure golden ingredients, the remaining 25%are other precious metals, and the common word prints are 750 or 18K.
(2) White K gold jewelry
The white K gold jewelry (referred to as white K gold), which is slightly yellowish white. For example, 750 white K gold is 75%gold and 25% The alloys of precious metals are 750 or 18K.