I found the following on an internet website about jewelry care:
All jewelry made from platinum, gold or silver tarnishes over time
from the process of oxidation. A film or thin layer of
discoloration develops on the exterior of these metals.
This created some discussion in our store with regard to whether or
not platinum jewelry can oxidize over time. My only concrete
experience has been with customers who bought platinum jewelry and
after the purchase, due to ill health and changed medication,
complained of discoloration. One specific customer purchased a large
platinum ring after years of buying gold from me, and thereafter was
required to take high doses of lithium. She came in highly upset
about discoloration to her rings. I don’t know that this was an
oxidation issue, but we determined it was a chemical reaction due to
the PH change of her skin. She had worn the ring for half a year
with no problems.
Having found the above quote I did a search of the internet for
further and found other comments about heirloom jewelry
made of platinum “darkening to a dull gray” over time.
I’d like to hear some thoughts on this since platinum is primarily
recognized as being oxidation resistant.
It all depends on what it is alloyed with, pure platinum will not
oxidize but several of the common alloying metals will (cobalt,
palladium, copper, tungsten) so if the jewelry is made from an alloy
that includes one of the aforementioned metals then yes it can
oxidize.
James Binnion @James_Binnion
James Binnion Metal Arts
The “darkening to a dull gray” that you are referring to is actually
the result of microscopic scratches that form on the surface of the
jewelry over time from wearing the piece. This causes light to
reflect differently from the surface than on a brightly polished
piece.
This of course is in reference to Platinum of 90% or higher in
quality. The 585 Platinum that is on the market may oxidize over
time but I have not seen any older pieces yet to know.
Contrary to popular belief, platinum is a grayish metal, not white.
It is usually plated with rhodium to give it that white look. When
the rhodium eventually wears off, platinum will appear in its
normal, grayish color and is not oxidized or tarnished. Scratches in
platinum will make it even more obvious. A satin finish on a platinum
ring is very attractive to me, like the one we had made for a
customer recently. In my opinion, the chrome tourmaline that was set
into it would have looked better in yellow gold, though.
It all depends on what it is alloyed with, pure platinum will not
oxidize but several of the common alloying metals will (cobalt,
palladium, copper, tungsten) so if the jewelry is made from an
alloy that includes one of the aforementioned metals then yes it
can oxidize.
Palladium oxidizes?! It gets greyer or what? Just wondering as we
have just started using this alloy and so don’t know what it does
over time…I see photos in magazines of very delicate pieces done in
palladium with pave and all and I wonder because it’s so light–it
just doesn’t seem to have the mass I associate with things holding up
over time.
G’day; When one considers that platinum and gold have lain in the
ground for many millions of years before being brought to the
surface by some means, they are always found to be shiny bright and
free of scale of any kind. (I have seen tiny granules of platinum and
bigger pieces of gold panned from a stream; they were both bright and
unmistakable.) So it must seem that platinum and gold are not metals
that combine easily with oxygen. The fact that they dissolve or
alloy with each other cannot be called oxidation. It is very
difficult indeed to make either gold or platinum oxides. Perhaps
combination with chlorine, bromine, iodine or fluorine (the halogens)
might by some be termed a sort of oxidation but I doubt that such a
reaction would normally be called oxidation. These two metals don’t
easily combine with sulphur either (unlike silver) So I would suggest
that any discolouration would be due to haze from wear, or some
reaction with an included alloying metal.–
Cheers for now,
John Burgess; @John_Burgess2 of Mapua, Nelson NZ
There is a good article by JJMaertz about the nature of various
Pt-alloys in
I did experience the color change of Pt/Pd system by heating the
metal at low temp. It was gray-brownishi colour, but shoud be
variable depending on the condition.
Yes it does, Palladium develops the most beautiful blue oxide when
heated. It doesn’t seem to oxidize visibly at room temps though.
However I have not looked at palladium that has been worn for many
years to see if it shows any visible oxidation.
Jim
James Binnion @James_Binnion
James Binnion Metal Arts