Im afraid this is the best i can do for the moment, until I can find something better or have time to make one
this is as far as I got in Mineral gathering, i have not been to all the maps yet & I only got as far as Grade B gathering, but I'm pressuming that Grade A Minerals will be on the Mangrove map
E= orange (in all town maps, will add later)
D= yellow
C= red
B= blue
A= purple (when I add to it)