A hallmark is used as an indication of the metal content in precious
metal jewellery and is usually stamped into the piece.
A hallmark should (see fake hallmarks below) guarantee the purity of the metal as determined by assaying (testing) the metal by one of several methods.
Some of these assay methods are destructive but highly accurate (to 1 part in 10,000) and used to test random samples from a manufacturer for compliance. Other methods are completely non-destructive but with a corresponding loss of accuracy (around 2 to 5 parts per 1000) and these would be used during a jewellery valuation to test a piece assumed to be of value.
|.999||99.9% gold||24 carat|
|.916||91.6% gold||22 carat|
|.750||75% gold||18 carat|
|.583||58.3% gold||14 carat|
|.417||41.7% gold||10 carat|
|.375||37.5% gold||9 carat|
|999||99.9% silver||Fine Silver|
|925||92.5% silver||Sterling Silver|
|900||90% silver||Coin Silver|
a large amount of fake jewellery has been found for sale on Ebay. The
items are typically manufactured in China and are stamped with "925",
the mark for sterling silver.
They are clearly NOT sterling silver as is evident by the prices. There is a world price for silver and these items are being sold for less per gram, than refined silver can be bought. As shown below a 35 gram bangle for $12 (about 1/3 the cost of silver bullion)
As with all purchases, if it seems too good to be true, it probably is!
One of the manufacturers falsely labeling their products was
quoted as saying, "We do it because it makes it look better for the
customer." Seriously? The customer is being ripped off and not getting
what they believed they had paid for.
Falsifying hallmarks damages genuine jewellery businesses who rely on the hallmarking as an assurance of quality. China in particular needs to be brought to task with a ban on all imports until this practice is stopped. Until then, it's still buyer beware for those purchasing goods sourced from unregulated countries.
Here is a link to a range of websites advertising replica Tiffany jewellery, complete with the characteristic green bags and Tiffany logos: Tiffany Fakes
Here is an item found today (9/11/2012) on ebay.com.au advertised as:
Classic 925 STERLING SILVER Round 65mm charm Bangle NEW - $11.99 (free postage) LINK HERE
Condition:100% brand new, never be worn.
925 silver(925 stamp)
Nickel free, not allergic,not easy to tarnish
It is simply not possible to sell a genuine sterling silver bangle including a pouch and postage and handling from Hong Kong at one third of the cost of the raw materials. (35 grams for $12)
All our chains are hallmarked either 375 (for 9ct gold) or 925
(sterling silver) On the thicker chains you will find this on the clasp
of the necklace or bracelet. On the finer chains you will find this on a
tag that joins the clasp to the chain.
Some of our charms are NOT hallmarked, but they are absolutely guaranteed to be either 375 gold or 925 sterling silver. This is because both the silver and gold charms are sometimes made in the same mould and then hand finished. (You couldn’t have both hallmarks in the one mould, so there are none.)
Please visit Silver Marks, Hallmarks and Maker’s Marks for much more detailed information that covers antique and vintage silverware and silver plate.
Various assaying techniques are described in detail on this wikipedia page.