For what it’s worth. When I was in active practice, I cannot
recall using a gold alloy containing chromium. The constituents
of the alloys varied depending upon the particular purpose for
which it was being used. For example, if we were constructing a
fixed prosthesis (bridge),which required strength and wear
resistance, aType C gold was prescibed. This was a designation
of a gold that had the requisite physical properties deemed best
for the situation at hand.
The exact formulation was a guarded secret of the manufacturer
of the alloy, but they had to meet certain specifications laid
down by our professional organization. The usual constituents
were: Gold ----to yield between .667-750 fine (16-18K)
Nickel --% varied depending upon hardness desired
Palladium )--not always
Platinum ) "
Zinc--- small amounts
However, I was never aware of Cr. being used. I’m sure Skip can
throw some light on this.
Best regards Joe Dule