Landmark™: Tier 2 Minerals and Gems

Iron and silver can be found on Tier 1 islands. Rest will be found on Tier 2 and 3.

Iron
 Iron is easy to find. Just continue to dig past it. The best way to find silver is to find iron. Silver can be found underneath the iron most of the time.

Silver
Occasionally can be found on the surface but mostly found underneath iron.

Aquamarine

The common gem of the tier. Fairly easy to find. 

Topaz
Very difficult to find. Can be found underneath a surface vein of silver. Closely resembles tier 3 gold so be careful. There is a subtle difference in how it looks.