Things like coal, iron, aluminum & saltpeter, not horses.
(I think the response should have been inorganic)
Now a questions for the experts out there:
I have a recently acquired city with 2 native & 2 foreign citizens. It's about to complete a settler. What will the composition of the settler be? (0-2, 1-1 or 2-0). I need to found a new city near to the AI capital and if this settler would be both foreigners, then I'll send him to another island where I also need a new city. If the citizens are mine then I will found at the border with this settler (much less flip risk). Since my opponent has nearly double my culture and will claim a critcal resource, this is an important decision to be made. My next available settler is 4 turns away and I'm worried about the AI getting there first.