Fair enough.
And his pick ?
And let’s not forget the fabric covering on his amplifier.
Neil Young uses Herco Flex 50 picks, which are made of nylon.
His in particular I don’t know.
There are some exotics for folks that like to spend money, bone, horn, etc
http://www.dugainpicks.com/
Most I believe are made from Nylon or Celluloid.
To create nylon, the manufacturer combines two sets of molecules. One set has an acid group on each end, and the other set has an amine group.
http://www.wisegeek.org/how-is-nylon-made.htm
Celluloids are a class of compounds created from nitrocellulose and camphor.
http://www.plastiquarian.com/index.php?id=53&osCsid=010058e19c10be59939e62a4c5b10e4e