[Alneyan]

I didn't recall that about Dom 1. Hmm... So, in Dom 2:

* In the Pretender descriptions, the Daughter of the Land is said to bring two water gems per season.
* Magic items: the Clam of Pearls is said to bring one astral pearl per season. The Blood Stone produces "a small amount of magic Earth gems each year"; the "small" part might be confusing, as it still produces one gem per turn, as the other similar items.
* Spells: Eternal Pyre is said to produce 20 fire gems each season, while it does so every turn.

These are the ones I can recall on top of my head; there may be a few other descriptions where seasons are used to describe turns.