I went to zhouliufu and bought a pair of gold earrings with diamonds. When I got them back, some people said that gold could not be set with diamonds. I wonder if the diamonds are really crystal stones

I went to zhouliufu and bought a pair of gold earrings with diamonds. When I got them back, some people said that gold could not be set with diamonds. The diamonds are not real crystal stones. I wonder if they are real or fake?