Answer:
I am the fountain from which no one can drink. For many I am considered a necessary link. Like gold to all I am sought for, but my continued death brings wealth for all to want more.
Different lights do make me strange, thus into different sizes I will change.
As I walked along the path I saw something with four fingers and one thumb, but it was not flesh, fish, bone or fowl.
It's usually found dried, but often kept slicker. Above another need, it's said to be thicker. What is it?
The higher I climb, the hotter I engage. I cannot escape from my crystal cage.
If lightning strikes an orchestra who is the one most likely to get hit?
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?