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3.6 KT / 15% Gilt Gold!

ZoinsZoins Posts: 34,287 ✭✭✭✭✭
edited July 24, 2020 7:58AM in U.S. Coin Forum

I follow So-Called Pilgrim Jubilee Dollars and just ran across this HK-15A which is a whopping 3.6KT or 15% gold!

My first thought was that's a lot of gold for gilt / plate!

I added the photos below. How likely is this to be 15% gold?

https://www.ebay.com/itm/1870-Pilgrim-Jubilee-Memorial-So-Called-Dollar-Coin-Whose-Faith-Follow/164301905853?

I wonder if mine is 15% gold now too!

Comments

  • rickoricko Posts: 98,724 ✭✭✭✭✭

    It would appear (and I may be wrong) they are just quoting the amount of gilt/plating use on the base metal. Cheers, RickO

  • ZoinsZoins Posts: 34,287 ✭✭✭✭✭
    edited July 24, 2020 8:05AM

    @ricko said:
    It would appear (and I may be wrong) they are just quoting the amount of gilt/plating use on the base metal. Cheers, RickO

    I'm guessing it could be purity of gold in the gold plate or purity of gold in the entire medal.

    I'm not really sure how these spectrometers work.

    If it's just the purity of the gold plate, that's some cheap plating. These days even the National Collectors Mint uses .9999 Pure Gold!

  • keetskeets Posts: 25,351 ✭✭✭✭✭

    I feel it's overall Gold content.

  • BStrauss3BStrauss3 Posts: 3,454 ✭✭✭✭✭

    XRF goes a little below the surface, but not much - how far depends on beam power.

    https://www.horiba.com/us/en/scientific/products/x-ray-fluorescence-analysis/tutorial/penetration-depths/

    and

    https://www.edax.com/-/media/ametekedax/files/resources/tips_tricks/analysisdepthsformicroxrf.pdf

    If gold has a maximum depth of 8um and it was plated with 24kt gold, to read 3.63% would mean a plating thickness of around 1.2um over pure copper to read as 3.63%.

    -----Burton
    ANA 50 year/Life Member (now "Emeritus")
  • CaptHenwayCaptHenway Posts: 32,226 ✭✭✭✭✭

    That looks like a high grade gold surface. Perhaps it is just reading the surface and a little depth below that and averaging out to 15%.

    Can you test the edge just for the heck of it?

    Numismatist. 50 year member ANA. Winner of four ANA Heath Literary Awards; three Wayte and Olga Raymond Literary Awards; Numismatist of the Year Award 2009, and Lifetime Achievement Award 2020. Winner numerous NLG Literary Awards.
  • JimnightJimnight Posts: 10,846 ✭✭✭✭✭

    Beautiful!

  • CaptHenwayCaptHenway Posts: 32,226 ✭✭✭✭✭

    And a good specific gravity test will tell you what the true content is.

    Numismatist. 50 year member ANA. Winner of four ANA Heath Literary Awards; three Wayte and Olga Raymond Literary Awards; Numismatist of the Year Award 2009, and Lifetime Achievement Award 2020. Winner numerous NLG Literary Awards.
  • ZoinsZoins Posts: 34,287 ✭✭✭✭✭
    edited July 24, 2020 5:18PM

    @CaptHenway said:
    That looks like a high grade gold surface. Perhaps it is just reading the surface and a little depth below that and averaging out to 15%.

    Can you test the edge just for the heck of it?

    Good idea, but mine is in the NGC MS66PL slab. The raw one with the spectrometer test is offered on eBay and isn't mine right now.

  • KliaoKliao Posts: 5,571 ✭✭✭✭✭

    I don’t know about the one the seller is using but the one in the LCS I work at will tell you if it’s plated or not.

    Collector
    75 Positive BST transactions buying and selling with 45 members and counting!
    instagram.com/klnumismatics

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