[MLD-Grounds-Keeper-Willie]

Well I really can't tell you that much on it but, the dwarves, isolated themselves from the rest of Middle-earth, so they probably kept the mithril for themselves. It could be traded in the dwarf race, but if they coveted it so much as a precious metal, it was very likely that they tried to keep it with the dwarves. And if it did get out, it was probably traded with the elves for a handsome price, and then, the elves, molded it to greatness, and imbuning special qualities or whatever.

And. it seems that mithril is so rare that they kept it in their race, and it became something that they were known for. And if it was so rare, there probably wasn't that much to go around anyways...

Hope that helps...it's just my opinion...I don't know for sure...