Makes me think, "upwards flow", such as this:
Then we have "this is how we become rich":
|Olivine, of which peridot is a type, is a common mineral in mafic and ultramafic rocks, and it is often found in lavas and in peridotite xenoliths of the mantle, which lavas carry to the surface|
Peridot olivine is mined in Egypt, North Carolina, Arizona on the San Carlos Reservation, Hawaii, Nevada, and New Mexico at Kilbourne Hole, in the US;
The results from the above...
And let's not forget about threads like these: Why are all guns green?
- I also recall reading early on, shortly after Trailer 1, that the colour green would have more to do with the game than we think.
Not buying it? How about - an extinct Volcano's caves:
Caves formed from an extinct Volcano found in the mountains up in the north area of the map (that we've seen NOTHING of yet), which also have real life crystal caves.
For example, such as this real life cave formed from an extinct volcano in Portugal.
What do you think? None of this might hold much light to it, but I thought it was a fun idea anyway.