I have lots of metal rock. Could you please give me some ideas on how to get the most value for it to donate? Making expensive tools like Grand ol Grinders? Thanks in advance.
I recommend making crystalmalyzing chambers. They're worth 2500 currants, which gives you 250 favor per chamber (or 750 per chamber on EHSP). They take 20 metal ingots and 1000 shiny (from 167 sparkly rock), which makes the required 20 molybdenum ingots. I don't know if they net you the most favor/currants per metal rock, but they are certainly the least time consuming of all the items to make given how much they are worth.
Awesome pots provide a pretty good return but since you make them one at a time they tend to be a bit slow.
Also most of the tools that involve using planks in their making have a nice return on the bars like high class hoes. The high class hoe uses very few elements in its making for a relatively expensive tool.
The Irrigator 9000 is pretty nice too since it uses mostly tin which is cheap to make. You get a lot of bang for your elements out of tin ingots.