Are the 'good' greens map specific?

[Formora]

I'm pretty sure it was uncharted we were in, about three hours ago, when all five got a green drop from a chest! I got
Sandstorm arms!

Congratulations! That's pretty lucky.

I see. I have to keep my eyes out for these special chests. I always seem to see the same chests in the same spot, so maybe I'm missing these special chests or I've been extremely lucky to have them almost every time

The leggy ones? Dayum...

*Elar has invited you to Numa Prime - Uncharted Ruins!*

I kid, it's great that everyone's so lucky