I was talking with a few people today about their preference for
metals - silver vs white gold vs yellow gold, and the topic of
rhodium came up. One woman swore up and down that she owns a rhodium
ring that turns her finger green, and views it as a poor choice for
jewelry. I’ve honestly never heard about it doing that, but I also
don’t work with rhodium. I suggested maybe her ring wasn’t plated
right, or that the plating has worn away and the base metal under the
rhodium is what is turning her finger green, but I wanted to check
and see if I was mistaken that it is possible for rhodium to cause a
reaction like that.
It does indeed seem to be an odd claim. There is very little in the
way of rhodium jewellery about but rhodium plated items are very
common, most white gold and bright cut silver is Rh plated. Might she
mean something else or perhaps it is a piece of plated base metal
(copper or brass) that have given her the problems. I have seen a lot
of cheap costume jewellery retailed by the likes of Avon that is Rh
plated copper.
The green colour is normally an oxide or other metal salt deposit on
the sking that gets rubbed in when it causes a reaction and
sensitising to that metal. Nickel and chrome are the commonest green
deposit metals that you should avoid and it used to be common to find
these in plated jewellery. A Ni flash plating is still used
underneath other metals when plating steel (and others) hence the
need for a nickel leak test where there is not an outright ban.
If I remember my flame tests from Chemistry, the flame for Rhodium
is a reddish brown. Given the ladies finger is turning green, it would
be to me, that she is being exposed to copper. I would have her take
it in to a jeweler than can test the ring.
Thanks everyone, I passed the on to her and suggested
she see about replacing or returning the ring from the company she
ordered it from. I haven’t seen the ring in person to look it over or
test it for her, but my guess is that it’s not plated correctly.