Answer:
A box without hinges, lock or key, yet golden treasure lies within.
They are many and one, they wave and they drum, Used to cover a state, they go with you everywhere.
The ones who see it may go blind, Contracting the fool's madness. You have to dig to find it, Crush big stones or mine it. Wash dirt clumps in a pan and wait for it to settle, A shiny, precious metal.
We are five little objects of an everyday sort, You will find us all in a tennis court.
Long and slinky like a trout, never sings till it's guts come out.
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.