Coin Conservation with Olive Oil?

Discussion in 'Coin Chat' started by fretboard, Aug 31, 2020.

  1. fretboard

    fretboard Defender of Old Coinage!

    I'm working on a copper Token and I'm trying to make it darker. What would you use to make it darker, Olive Oil or Verdi-care? And is it extra virgin Olive Oil or the promiscuous stuff? laughhard.gif j/k Anyone have experience with Olive Oil and working with copper?
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  3. desertgem

    desertgem Senior Errer Collecktor Supporter

    Olive oil has an average pH of 6.6 which makes it an acid, even though it is from fatty acids, over time it will brighten like a cent in coin dip. You want something to put a darker oxide over the current surface. Jewelry supplies have "patina" solutions for most metals, but don't do it! Jim
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  4. lordmarcovan

    lordmarcovan Eclectic & Eccentric Moderator

    I don't like olive oil, except on roasted potatoes. I prefer mineral oil or Vaseline for removing surface contaminants on copper without affecting its color.

    And if I'm trying to darken a coin, I use a paste of powdered sulfur and Vaseline, of which a friend mixed up a batch for me some years ago. That is basically the same thing as the product sold under the name "Deller's Darkener", though my "Herschel Sutton's Formula" is stronger than Deller's. Must have more sulfur in it.

    I've had olive oil leave a sticky residue on coins, and even had it go rancid once. Ugh.
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  5. Silvergmen

    Silvergmen SILVER & MORGAN Obsessed

    I use the heck out of olive oil in my cooking and none on my coins.
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  6. John Burgess

    John Burgess Well-Known Member

    I just leave my cents in a jar that's open if I want then to turn dark then give it a couple years.
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    GDJMSP Numismatist Moderator

    Both of those will make brighter, (the olive oil more so), not darker.

    If ya want dark, this is what ya want -

    But personally, I advise against it.


    While olive oil has long been a favorite of many as a coin "cleaning solution", it is a very poor choice for several reasons, the one mentioned above being only one of them. Another is that it takes almost forever, months and months at times, to do much. As Jim mentioned above, it's acidic, but it is a very, very weak acid. And once you use it, well, you still need to properly clean the coin just to get the olive oil off of it. Xylene will work best for that.
  8. Mike185

    Mike185 Well-Known Member

    Hard boiled eggs!! Sounds dumb but has good amount of sulfur.. smash them up in a container with a lid and place the coin next to the eggs. Afterwards you can make a salad....
  9. kanga

    kanga 65 Year Collector Supporter

    Olive Oil or Verdi-care

    Both will lighten the color of copper.
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  10. halfcent1793

    halfcent1793 Well-Known Member

    Deller's Darkener is sulfur ointment. Sulfur corrodes copper. DO NOT USE IT! It will destroy your coin eventually.
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  11. John Burgess

    John Burgess Well-Known Member

    trying to make it darker..... hmmmm. shot in the dark, and test on some other copper you don't care about like the plated lincoln cents FIRST as an example, but I've had luck going shades of brown darker with baking soda dissolved completely in hot water then dabbing the surface with a cotton ball and letting it sit to dry for like an hour and see where it's at, then reapply, with sulfur of any sort you run the risk of going black instead of brown and I'm guessing you are looking for a deep chocolate brown color. this will tone it brown a little at the time, especially if you make a weak solution ( I suggest measuring everything in case you want to replicate or make adjustments to the recipe) maybe a teaspoon of Baking soda and a cup of water to start and test it to see how it does. when you are done rinse in distilled water, or rinse with distilled water between each treatment if you do it over a period of time and take breaks.

    the olive oil thing or mineral oil was really more about "protecting the surface" to keep dust particles off the coin or breathing spit. and people that oiled their coins would also need to clean them of the thick build up, the oil would work as a protective layer, but a bit easier to remove than lacquer. it's not really for toning or darkening or lightening coins.

    time, environmental factors, and luck is what it really takes, all artificial methods won't quite be the same result.

    And I will say this, humidity helps a lot to speed up toning. while dry environments it will happen at a snails pace. if you can make a
    I mean if you could take a small container or jar and put a platform in it, and a couple drops of water and seal it and stick it on the windowsill, it would probably tone pretty quickly as the air in the jar gets real humid and damp, but this might lead to spotting from condensation. Something like this would speed it up on it's way to dark brown I think.

    whatever you do, test on stuff you don't care about and learn first, then take the gamble with as much knowledge as you can get with the piece you want to do.
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  12. Maxfli

    Maxfli Well-Known Member

    I've used Verdi-Care (great product!) extensively and have not experienced any change in color, lightening or otherwise. What am I doing wrong? :D
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  13. daveydempsey

    daveydempsey Well-Known Member

    Bury it in Sulfur or sulphur powder for an hour, the longer the darker it goes.

    Or put it in a brown paper bag with a banana skin or boiled egg.

    I've used virgin olive oil for years to clean off verdigris from 200-300 year old British copper coins that have been found with detectors or just stored in damp conditions.
    The longer you soak them the brighter they get.
    Last edited: Sep 1, 2020
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  14. Chip Kirkpatrick

    Chip Kirkpatrick Well-Known Member

  15. Collecting Nut

    Collecting Nut Borderline Hoarder

    I only use olive oil for cooking. And olive oil will make the coin brighter, not darker as you want. Just set it on a paper towel and put it in a sunny window for a lengthy time frame. Then flip the coin over and repeat for the other side.

    Why you want to do this is insane to me and nothing you say can change my mind. I may gain an understanding but it won't change my mind. Darker coins are very undesirable in today's coin market.
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  16. fretboard

    fretboard Defender of Old Coinage!

    Actually there's a video on youtube using hard boiled eggs to darken copper, so I know it works. :D That said, time for me to give this Token a rest so I can think of a better strategy! ;) I appreciate the feedback on Olive Oil tho' as that's something I've never used before! thumbsup.gif
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  17. Collecting Nut

    Collecting Nut Borderline Hoarder

    Sounds like a good plan.
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  18. Mr.Q

    Mr.Q Well-Known Member

    Same answer to an older than old question! Unless it's an ancient never consider cleaning a coin... Follow the leaders in my opinion.
  19. daveydempsey

    daveydempsey Well-Known Member

    Some people soak them in olive oil or other chemicals for to long and make them go brighter.
    Sulfer returns them to their natural shade.
  20. juris klavins

    juris klavins Well-Known Member

    Darken copper with brown patina
    1. Clean item with a clean lint-free rag dampened with clear, grease-cutting household cleaner.
    2. Add baking soda to hot water until it will no longer dissolve, and fill spray bottle with this darkening solution.
    3. Spray item with darkening solution.
      • Use cotton swabs dampened with the solution to wet hard-to-reach places.
    4. Allow to sit for an hour, and reapply to achieve the brown, copper penny finish you want.
      • Brown darkening solution will not powder like green solution.
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  21. lordmarcovan

    lordmarcovan Eclectic & Eccentric Moderator

    I had never heard about the boiled egg angle until this thread, but it makes sense. Interesting.
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