This is a thin foil of chromium electroplated on nickel foil, from the Flex-n-Gate manufacturing plant in Urbana, Illinois.
My van had broken down (bad battery) and I was waiting at Peter B's repair shop for them to put in a new one. I noticed I was sitting with nothing to do just across the street from what bills itself as the largest manufacturer of automotive bumpers in the country, Flex-n-Gate. I immediately thought CHROMIUM and took a walk over to their front office.
The receptionist seemed a bit confused about who she should direct me to, but finally went in back to find an engineer: Presumably she thought he would at least know what I was talking about.
The engineer, Douglas Suits, was very understanding, and I showed him some photographs of the Periodic Table on my PowerBook. He said he would check around for some samples, and later that day I went back to pick up an envelope containing this flake for chromium and two very nice chunks of nickel (see).
Unfortunately, while they receive nickel in metallic form, chromium arrives in the form of chromic acid because that is more convenient for electroplating. So while they probably have more chromium in one place than almost any other place on earth, he was unable to give me any. They have so much nickel they actually have to keep a guard on it because of its value, but presumably no one wants to steal chromic acid!
He explained that bumpers are actually not primarily plated with chromium but rather with nickel. They electroplate 0.0010" of semi-bright nickel, 0.0003" of bright nickel, and only 0.000000066" of chromium onto the base of steel.
Source: Flex-n-Gate, Inc
Contributor: Flex-n-Gate, Inc
Acquired: 25 April, 2002