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Thread: Hallmarking Queries

  1. #71
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    Jasdir, im not sure its possible to do without filing a bit away, what is it exactly you are trying to do?

  2. #72
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    Sounds like it would certainly at least have to remove the plating from one part. Maybe email one of the assay offices?

  3. #73
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    Jun 2014
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    Hallmark means a mark on a article/piece which guarantee the purity of that precious metal.
    I thought that hallmark means full satisfaction of purity, But, if they aren't fully capable of testing the purity of any article/piece, Than hallmarking is for what ? nothing I think.

    I thought they might be having any other machine (other than XRF) which is capable to test any ready article/piece of precious metal down to core. But, now, after your replies am sure that there isn't any such machine, and Hallmark is just an useless mark paid for

    No need to contact any assay office, because I already know how they will justify this stupid guarantee.

    So, for me "Hallmark" = "Stupid-Guarantee"

    Anyways, Thanks for your input, both.. Unhindered & LydiaNiz.

    Jasdir.
    Jewelry for today's world,
    Whereby, style following the pattern of traditional world !

  4. #74
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    if its plated (has a non precious metal core) i dont think they can hallmark it anyway

  5. #75
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    Feb 2016
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    I believe that the purity in an item with a metal core may not necessarily be ascertained but the impurity can be.
    If a piece is described as solid 9ct gold the Archimedes principle can be used to calculate whether the gold is pure 9ct (see Archimedes, eureka on any search engine)
    If the piece declares a metal core it would be marked as plated or rolled gold.
    In short, math can be used to check expected mass against actual mass thus revealing purity.

    Does that clarify or am I missing the question?

    It is confusing because historically in other countries plate was marked as gold. I have a pair of earrings that I bought in Malta in 2002 which are marked 9kt but they are plate. The British system does differentiate in the same way that Victorian silver maybe marked with a lion (silver) or the letters EP (electroplated silver)
    Last edited by Ceri; 01-06-2016 at 01:57 PM.

  6. #76
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    Jun 2014
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    Bathinda, India, India
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    Quote Originally Posted by Unhindered View Post
    if its plated (has a non precious metal core) i dont think they can hallmark it anyway
    How will the assay office measure purity if a very thick layer of precious is rolled on any cheap metal ?
    Hence they can make a mark, yes.
    Jewelry for today's world,
    Whereby, style following the pattern of traditional world !

  7. #77
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    Jun 2014
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    Bathinda, India, India
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    Quote Originally Posted by Ceri View Post
    I believe that the purity in an item with a metal core may not necessarily be ascertained but the impurity can be.
    If a piece is described as solid 9ct gold the Archimedes principle can be used to calculate whether the gold is pure 9ct (see Archimedes, eureka on any search engine)
    If the piece declares a metal core it would be marked as plated or rolled gold.
    In short, math can be used to check expected mass against actual mass thus revealing purity.

    Does that clarify or am I missing the question?

    It is confusing because historically in other countries plate was marked as gold. I have a pair of earrings that I bought in Malta in 2002 which are marked 9kt but they are plate. The British system does differentiate in the same way that Victorian silver maybe marked with a lion (silver) or the letters EP (electroplated silver)
    Ready article/piece can also carry studded stones etc. Hence Archimedes-principle cannot be applied in such cases.
    Does assaying offices refuse any such articles/pieces for hallmarking ?

    Anyways, I also don't think that assay office apply both XRF, and as well as Archimedes-principle on each and every article/piece before hallmarking. (Even when the article/piece does't carry stones etc. )
    Jewelry for today's world,
    Whereby, style following the pattern of traditional world !

  8. #78
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    Nov 2010
    Location
    London
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    When I went to Art in Action a couple of years ago the LAO was there with a special machine that they placed items on and it produced a graph of the various metals present. One of my rings turned out to be 18ct - the other came to very very slightly under 9ct and as I said I would probably melt it down to re-use at some point they advised adding a small amount of higher purity gold to it so that I could be confident it would get a 9ct hallmark. I don't know whether this was an XRF machine?

    It's my understanding that they do test each and every item - if they need to scrape the surface away then they will and they are diligent in only awarding justified hallmarks. I know somewhere I have read of people sending pieces for hallmark only for them to be refused as components were not what they claimed to be, so they do reject items.

  9. #79
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    Feb 2016
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    I believe that the Archimedes principle could still be applied but it is more likely that this http://www.oxford-instruments.com/in...recious-metals is used which should be enough information to apply/deny a hallmark on basis of plate/solid and also check the gemstones simultaneously so the piece can be stamped if required.

    During the Georgian era, the Archimedes principle was used to check weights for hallmarking hence the variable gold content of 18ct gold rings from that date (18-21ct in purity) because anything under 18ct would be refused to be recognised as gold until a later law in Victorian times recognised 15ct (In Britain) and 14ct (In America) and later still 9ct (8ct in America)

    British Hallmarking standards are recognised the world over. They would not jeopardise their reputation by stamping anything that isn't to standard.

  10. #80
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    My assay office Edinburgh, doesn't mark plated metal and they do indeed test every piece that is sent in Jasdir
    Last edited by CJ57; 01-06-2016 at 04:10 PM.

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