Well I sold these prematurly as I got scared that the person in charge of this merchant would be pulling something but this is what I got out of it.
(Day 1 where I just started to buy them)
(Day 5 where I sold, I got sketched out so I sold them at minimum so I only made about 200gp per a diamond, but apparently the clan dumped their diamonds during the afternoon. They told me their diamonds sold so if I sold mine at the medium price I would have made 2mill, but like I said again its just by word that they sold it all. Im happy walked away with like 1mill and some change.)