All islands have an extra tasks menu at the bottom left. It will help you to easily find the resource you need.

Resources

There are lots of resources in the game that you can make use of. Here's what the resources and their deposits look like:

 ResourceDeposit
Grass

 
Wood

Stones

   
Iron Ore

Clay

Crystals

Orichalcum Ore

Cobalt Ore

Mithril Ore

Silver Ore

Gold Ore

Malachite Ore

Marble 

Diamonds

You'll find these resources on all the islands you can explore in the game, including temporary locations and endless islands.

The portal to endless islands is on the right side of the camp. 

To find resouces on the endless islands, use the resource menu in the bottom left corner.

If you run out of resources on an endless island, find a portal and move to the next island to start collecting resources from scratch.