|Broken and polished plate.
This lovely, and quite substantial, 1/2" thick slab of chromium is NASA surplus. Not sure what they were doing with it, but I'm sure it was exciting and involved trips to mars or something. It came with two sides coated with thick green oxide. I've never quite understood why chrome (and ferrochrome) is found with this kind of oxide on it. Chrome does not oxidize on its own in air: People electroplate it onto steel precisely because it stays shiny indefinitely. The slab must have been exposed to either chemical or electrolytic attack at some point.
At Ethan's urging I machined, lapped, and polished one face to a mirror finish. This is appropriate since so much of chromium's uses involve putting a mirror finish on something that normally doesn't have one.
Source: Ethan Currens
Contributor: Ethan Currens
Acquired: 1 July, 2006
Text Updated: 19 November, 2007