Golden Timberblock, so this is it

No matter how I look at it, it looks like wood... I went back to the starting town and looked again, and there's a hint here. (Screenshot 1) If you're still in town 1, mine the golden trees when you see them. You have to process and sell them to complete the quest. If you've already passed this point, upgrading your wood-cutting machine will increase the drop rate. So if you go back after some time, it should be there. Again, you need to process and sell it... (Screenshot 2)