when was chrome first used

Chrome plating was tried as early as the 1840's.
But may not have been very good, or very common, or well understood until
around 1900.
An early use was jewelry (linkable to medal-minting?).
http://www.dartmouth.edu/~toxmetal/TXSHcr.shtml copy

In 1798, Louis Nicolas Vauquelin discovered that he could isolate metallic chromium from samples of crocoite by heating the oxide in a charcoal oven. He was also able to detect traces of chromium in precious gemstones, such as ruby, or emerald. Later this year he successfully isolated chromium atoms.During the 1800s chromium was primarily used as a component of paints and in tanning salts:
Wiki: http://en.wikipedia.org/wiki/Chromium#History copy