It all depends on the soil conditions. Now, under strong magnification, it will be easier to see differences in natural and faked patinas. I would hesitate to give too many details because I don't have the pieces nor pictures with me, and second.....I know (as we on this forum have discussed in earlier posts) there are fakers that peruse this forum to improve their "craft".
I'll just say that I have lost interest in Luristan pieces, for example, because I have seen really good fakes where I could scarcely tell the difference in the green and brown patinas present (probably gave away too much information right there
).