So I have two questions pertaining to the stuff in the Forgotten Vale.

Where can I find all the Unknown Volumes and what is with the Gem Paragons?

I currently have volumes 1,3 and 4 of the Unknown volumes, and I don't know where vol. 2 is or if there is any past 4. I also have the diamond and emerald paragons, but I am not sure what they are for or if there are any others.

Any help or advice would be most appreciated.

Volume 2 can be had by one of the paragons. The paragons transport you to different areas that cannot be accesed otherwise. There are 5 of them. Take the unknown volumes to the orc in the college of winterhold and he will give you translated versions in place of them.

Thank you! I will continue my search