What's the difference between iron rust spot of Yuan blue and white and imitation iron rust spot?

Regarding Yuan blue and white porcelain, I have collected a few pieces before, and most people may laugh at my dreams. In fact, collecting Yuan blue and white porcelain is not a myth. As far as iron rust spots are concerned, Yuan blue-and-white porcelain has the following performances; Iron rust spots turn brown, magnified more than 60 times, showing reticular patterns, dendritic stripes, water ripples, vortex patterns and so on. However, the rusty spot of imitation iron is silvery gray, enlarged more than 60 times, showing a block shape without any change, which is very dim. This is an important basis for identifying blue and white porcelain in Yuan Dynasty. At present, there are many Yuan blue-and-white porcelains in China, which are not as rare as some experts and scholars say. I have seen no less than blue and white porcelain from 30 yuan, all of which have the above-mentioned reticulate features. At present, imitations on the market can't be achieved, because they are naturally formed for hundreds of years or even longer. Of course, some Yuan blue-and-white porcelains don't have the above status. I believe there will be a scientific understanding of Yuan Qinghua in the near future. In addition, porcelain in the early Ming dynasty also had the above state.