Does anybody know where I might be able to obtain spectrophotometric
data for the reflectances of various gold alloys (e.g. 9-24 carat
gold/silver; rose-gold etc...)?
Hoover and Strong did such a study some time ago, or so I remember.
It used to be in their catalog, but it's not in the new one. A search
of their technical articles on their website might turn it up. Even
if it doesn't, there's a lot of really good and interesting info
there that can keep you occupied for hours.
Best I can come up with.