From
http://www.patentstorm.us/patents/5660462-description.html
The envelope, at least in the portion having the reflective coating, preferably has an ellipsoidal shape, and the filament is located on or near the axis of the ellipsoidally-shaped envelope. The reflective coating is preferably formed on an outside surface of the envelope and may be selected from the group consisting of aluminum, silver, copper, chromium, nickel, gold, rhodium, palladium, platinum, and combinations thereof
From
http://www.freepatentsonline.com/5660462.html
5. A lamp assembly as defined in claim 4 wherein said reflective coating is selected from the group consisting of aluminum, silver, copper, chromium, nickel, gold, rhodium, palladium, platinum, and combinations thereof.
and from a 155 page report that i could not find it in as fast as the google engine did but i put it here for you to look into:
http://www.bmbikes.co.uk/photos/press%20PDF/1999%20Press%20Release.pdf
(platinum and palladium) as well as reduction (rhodium) being applied to a ...... lens to eliminate any deficiencies, the headlight reflector used here ...
so it seems there may be applications where it is used, but the values may be near small enough to be a waste of time trying to get them out....
Hokes book talks about Pt and Pd being easy to recover but does not cover the process to gather Rh in any easy manner in fact says that it can be quite hard to do so.... what method is anyone using to recover Rh??
William