Whit gold is generally plated in in the commercial jewellery markets
of the world with Rhodium for the purpose of making the white gold
look "bright white"...the naturay colour of white gold if some what
steely grey...but slight warmer in colour thanks to the Yellow gold
content...Commercialy speaking customers prefer the "bright white"
look expecially when diamonds are involved as it makes the stone
appear larger in its setting...
Talking of earrings or any other piece of jewellery...usually you
would complete the entire piece's assembly, buff, polish, set the
stones, buf again and then plate. This process really goes for any
kind of plating.
The other reason for rhodium plating to mention is that white gold
alloyed with palladium is a lot softer than rhodium and would scratch
a lot more...therefore by rhodium plating you add durablity to the
piece especially if its a ring....but this has alife span of about 6
months to a year before you would have to replate.
Nickle alloyed white gold is far more durable and far whiter than
its palladium alloyed counterpart but has the allergy factor.
There when I work with a white gold, I alloy my gold with palladuim
and offcourse silver for caratage...but i dont rhodium plate any of
my white gold work as I nor my clients have any issues witht he
natural colour of the palladium alloyed white gold.
So to answer your questions:
Do earring posts in white gold get rhodium plating?
Yes the do....
Or is the rhodium plating to hide a base metal?
It is possible but more likely to add a bright white colour or for
the durablity factor.
Why plate white gold?
As stated above to allow for less sctraching and for a bright white
finish especially for stone setting.
And how does rhodium plating work with people with nickel
The way it works is that the layer of metal that touches the skin is
actually the rhodium layer...which keeps the nickle part from comming
in contact with the person who is wearing it...but it depends on how
thick the plating is....it should be atleast 8 microns of plating
Also it was stated that white gold doesn't have nickel in it. What I
(think I) know is that American white gold is still made with nickel.
European white gold is made with palladium...and America should
follow their lead, but haven't so far.
Am I right about the alloy?
Yes you are right in that Yellow gold is mixed with either nickle or
palladium to bleech and acheive the white colour...yes the USA
predominantly uses nickle alloyed white gold, which is more difficult
to work with than the palladium alloyed white gold...When I worked in
Littleton Colorado, I met a really nice gentleman that was atleast 50
years in the business of setting stones and he refused to set
anythingmade in white gold becoz it was all alloyed with nickle and
too hard to set....I showed him how to alloy the gold with palladium
and he was quite happy to use that....
What is Canadian white gold? Nickel or palladium?
I am unaware of what is used as an alloy in canada.
I hope this helps....let me know if u should have any more
questionsab out this topic ofline if need be. I have worked in the
USA and and from South Africa and an currently working in India so
have a bit of knowledge from a few places...