 |
Hallmarking
 |
To
receive a ‘Hallmark’ items of precious metal must undergo tests
carried out by the ‘Assay’ office, to ascertain if the object’s
content of precious metal meets the standard requirements of
purity. Forms of marking precious metal objects were around
from the Byzantine period in the early |
|
part of the first millennium A.D. However, it was under the rule of king Edward I of England, known as ‘Longshanks' due to his size, that hallmarking was first established.
|
|
The
term ‘Hallmark' comes from ‘Mark of the Hall of Goldsmiths’
in London, who in 1327 were the first official ‘Assay’ hallmarking
office decreed by parliament to control the standard of precious
metals circulating in the British Isles. To this day they still
operate one of four authorized assay offices in Britain. |
|
Before
items made of precious metals such as Silver, gold or platinum
are stamped with an ‘Assay’s’ hallmark they undergo rigorous
testing to prove whether or not the metal purity measures up
to the established standards. In fact, the word ‘Assay’ is derived
from the French word meaning to test, trail or examine. |
|
The basic method of assaying, also known as the 'Cupellation' process, was first introduced by the ancient Egyptians. The process starts when a small sample of Silver is removed from the object to be tested, which is then carefully weighed and measured. |
|
| |
The sample of Silver is then placed in a ‘Cupel’, a small receptacle
made of bone ash, along with a small quantity of lead. This
is then placed in a furnace and heated to a high temperature
with a draught of air flowing over it. The lead and any other base metals contained
in the silver sample are either oxidized or absorbed into the
‘Cupel', leaving only the pure silver behind. |
|
| |
The remains of the silver are then weighed and measured and
compared to the initial weight of the sample. The ‘Cupellation’
process is the most accurate method for determining metal purity
and is the standard technique practiced today. Upon meeting the required standards of Sterling
Silver the item of Sterling is stamped with the appropriate
hallmark. |
|
|
|
Until
quite recently, most Hallmarks were ‘Struck' using steel punches.
The punches are produced in various proportions, appropriate
for petite pieces of jewelry to hefty items of Silver ware.
Punches are made in straight shanks
for normal punching with a hammer, or ring shanks used with
a press to mark rings. |
|
|
|
The trouble with traditional punching is that the procedurecan misshape the form of the jewelry resulting in the article having to be reworked after hallmarking is completed. For this reason unfinished items of jewelry are often sent to the assay office where cuts-offs are taken and tested from the articles before hallmarking is executed. |
|
| |
At present a new method of marking is using laser technology,
which burns the hallmark on to the jewelry, something which
is especially valuable for delicate items which would otherwise
be damaged by the traditional technique of punching. This procedure
of hallmarking uses |
|
high power lasers to dissolve material from the metal surface.
There are two methods of laser marking, 2D and 3D, 2 dimensional
marking burns the outline of the hallmarks into the object,
while 3 dimensional marking simulates the traditional punching. |
Often the hallmark is made up of several elements including:
the type of metal, the maker and the year of the marking. In
1999 a new format of English hallmarking on objects of Sterling
Silver was initiated consisting of a maker’s mark, the assay
office insignia and a 925 symbol. Optional extra marks are the
‘Lion Passant’, the UK sign of Sterling Silver, and the date
letter stamp. |
|
|
The standardizing of the date letter sequence, shared by all
four remaining assay offices in Birmingham, Edinburgh, London
and Sheffield, were introduced to bring the UK system closer
in line with other European Union
standards. However, the problem
remains that many
|
|
| countries throughout the world have different
standards and specifications that vary considerably, making
it difficult for one country to accept another's hallmarking
as equivalent to its own. |
| |
With the advent of globalization, ‘Free trade’ and the Internet,
finding the problematic solution to the standardization of world
hallmarking has become increasingly important. In 1972, the
EFTA (European Fair Trade Association) consisting of Austria,
|
 |
Finland, Norway, Portugal, Sweden, Switzerland and the United Kingdom held the
‘Vienna Convention’ where the first European hallmarking laws
for precious metals were put into force. |
| |
The convention enables specially designated assay offices throughout
member countries of the EFTA to apply, after testing, a common
control mark to articles of precious metals including Sterling Silver |
|
in accordance with the Convention. The articles bearing the Convention marks, called CCM: Common
Control Marks, are accepted without further testing or marking
by the assay office of any destination. country that is an
EFTA member.
Although this system is not worldwide as yet, Denmark, Ireland,
the Czech Republic and the Netherlands have since joined the
Convention. And Bahrain, France, Israel, Lithuania, Poland,
Spain and several Eastern European countries have shown an
interest in the Convention and are preparing for application.
|
|
|