Hi Maverick, Rhodium is a precious metal that is plated to prevent the
tarnish on silver. Although it is expensive, the effort of the
jeweller is by far the biggest cost.
The shop should have definitely asked your permission before charging
you 60 pounds.
It is possible that the original silver may have contained nickel as
an alloy or electroplated with nickel which would cause the green
I would further recommend that you should get the ring sent to an
assay office and get the purity verified.