Trade resources are defined in ImprovementDefs.XML; search that file for <ImprovementType>TradeResource</ImprovementTypes>.

UltraSpice, EpimetheusPollen, HeliosOre, ThuliumCatalyst, TechapodHive, ArtocarpusViriles, MonsatiumDeposit, CrystallizedElerium, XanthiumDeposit, AurorusArboretum, PromethiusStone, HyperSilicates, PrecursorNanites, HarmonyCrystals, and SnugglerColony are the internal names of the trade resources.

Ok, I have the resource showing up on my planet, but only in the bottom left corner. How is the X and Y calculated. Is 1,1 the bottom left? Is X left and right, and Y up and down?Is it based on positive numbers? Is it ONLY based on the actual existing tiles on the planet, or a grid regardless of computer generated usable tiles? Thanks.

That's just what I did, lol. I THINK I have it. (All read left to right)

Bottom row 0,0 to 9,0

1st row up 0,1 to 10,1

2nd row up 0,2 to 9,2

3rd row up 0,3 to 10,3

4th row up 0,4 to 9,4

5th row up 0,5 to 10,5

I'm pretty sure that's correct.