Guess I sold it to the guy who becomes werewolf then I killed hm and I do not have a save :( . Anything else I can use instead of the missing dimonds?
May spawning monsters then kill them will bring a loot dimond?

Head back to the ship and press ALT. After that, check every container. Anything considered a container will be highlighted. Do the same for outside.

If bad comes to worse, you can just use cheats to make some. The cheat for diamond is 00GEM26

There are a few in the Ice Temple too.