No matter which brand makes au750 jewelry, au750 refers to the proportion of gold in jewelry materials, au is the international gold code, 750 means that it covers 75% of gold, and the other 25 are other precious metals, which is commonly known as 18K! There are many colors, including white, yellow, red, green, black, blue and purple. Because of the different compositions and proportions of other precious metals, the most common colors in China market are white, yellow and red! Au750 has the advantages of high hardness and strong plasticity, and can make many special styles. It is the best material for inlay, firm and safe! The disadvantage is that because there are other precious metals, all 18K needs electroplating, so it is easy to show its true colors after electroplating for a long time. It's what many people call fading! Generally, all national chain jewelry brands are stricter than many self-operated brands in quality control, and the content is basically not bad, so as long as you like the style and choose Liu Fu, the quality should be no problem! But under the same material and weight, their prices will be much higher, which is the so-called added value! It depends on your needs! These consultants who usually sell things to you will not tell you so directly, because they take commission! I am a senior jewelry trainer. If you have any questions, I'll be happy to answer them for you!