Another fun history fact, because I'm on a roll. Until the 14th century, nobody really knew how to cut diamonds so they were usually exhibited in their rough form. Only a diamond can break another diamond, so I guess it took a little while to figure rhis out. It seems it was the Italians who got their in end - either the Genovese, Florentines or Venetians. Early techniques and technologies are not terribly well documented due to intense competition, meaning craftsmen closely guarded their secrets! .
This is the Lesedi la Rona - the largest rough diamond ever found (1109 cts WHAT!). Discovered in Botswana in 2015 it was sold to Graff for $53 mill. No biggie.