What generates gems?

[Endoperez]

Meglobob said:
In a MP game, I had the lucky event for nature which give me +22N gems in one go, wow!

Water and Nature have better gem-producing events. "Some water gems have floated ashore" and some spesific nature event. When you get blood slaves, you also get quite a lot of them. If you have hunters the amount won't be significant, but if you DON'T, few good events may GIVE you a hunter!