Larry, for starters take a look at: http://www.thegoldsmiths.co.uk/
which is The Goldsmiths Company, who operate the London Assay Office.
See also: http://www.teg.co.uk/teg/assay.htm for a bit more general
As regards your specific questions, a lot depends on your client. If
he/she thinks they may want to sell the ring at some time in the
future then really it should be given UK hallmarks. It could not
legally be sold here as “platinum” without either the UK hallmarks or
the international convention marks. These last were established to
cover international trade, but are only put on at official assay
offices after testing. It could always be hallmarked at a later date,
but then it costs more.
If the customer believes there will never be any intention of selling
it then maybe he will be happy with whatever you normally mark it with
There are at least two problems that arise if you want to get UK
The piece has to be submitted by a “sponsor” who is registered
with the particular assay office, and the piece will be stamped with
that sponsor’s assigned mark. I don’t know, but I suppose that it is
just possible that the folks at the London office might act as
sponsor, for a fee (for sure).
The assay office will take one or more small scrapings to test.
So, you need to submit the piece before final finishing, or else
negotiate with someone here who could carry out the final polishing (I
don’t do plat).
As regards Customs, the customer will have to pay import duty and
Value Added Tax. Or, he may be lucky, the package might not be
intercepted and he pays nothing. That possibility has never worked
for me though. You will probably want to use some sort of insured
delivery though, in which case it is moore likely to come to the
notice of officialdom.
All in all it looks as though your marks would be the simplest way to
go, provided the customer understands and accepts the difference
between those and the official UK hallmarks. A legal nicety might
hinge on exactly where the piece was sold. With your marks, as far as
I know (but don’t rely on it, I’m not a lawyer) it would be legal to
import a piece that has been bought abroad (i.e. outsdie the UK). But
it would certainly not be legal to sell it as platinum in the UK with
only your normal marks.
Hope this helps.
Kevin (NW England, UK)