So I wanted to see why the blue color never appeared on the penny so I did one rough test. I am SOO sorry for doing this but I was really curious. So I did this in 2 ways: one was burning (Im so sorry please don’t come after me) and the other was more like a list or a thing where my best looking copper pennies from fresh looking to almost a corroded green or red (Didn’t have any that had patina on them so i went with one that had an almost chocolate color). So that one copper penny that had to be burned needed to be cleaned from its milk chocolate brown color so i put 60% conc. Acetic acid and non-iodized table salt. I search online that the acid and the salt reacted to form sodium acetate and hydrogen chloride (hydrochloric acid) but this was from a website for children and their fun, interactive experiments. After the cleaned, almost unnatural looking, and pinkish orange color was present on the penny, I washed it with tap water to get rid of any aftermath products. I then rubbed it with a moist cloth to get anything that was still stuck. I then heated it until it reached the point where it was hot enough to react with the oxygen in the air to form a thin layer of copper oxide for the Thin-Film Interference Effect to happen. Simply, I think it is where an thin layer of a certain chemical is thin enough to interact with different wavelengths of white light. I did this until the penny turned blue and I expected this in my hypothesis because I heated copper before. Then I was confused because why didn’t this happen to room-temperature, environment toning. I read on a website to soothe my curiosity that the wavelength of the light reflected back towards me was dependent on the thickness of the oxide layer so maybe that environmental toning never got too thick or thin enough to reflect blue. Anyway my fingers hurt and here are the pictures: The one on the bottom represented similar toning to my altered penny when my altered penny was just a penny. I have multiple 1973-D pennies that looked almost identical to my original, now altered, penny. (So in a way, I did surgery to 1 of the nontuplets [now octuplets] I had). I am REALLY SORRY that I damaged an average copper cent. In my opinion, this penny does look more gorgeous and will have sentimental value to me, but you can criticize it if you want. Anyway that is all the interest I will have for 2 months I’ll see you later!! Picture of “Grading the Color of Copper Coins” by The Spruce Crafts. url:https://www.thesprucecrafts.com/copper-color-grading-768388
Shades of blue and or purple toning are actually fairly common on copper coins. You'll find quite a few of them here - https://www.google.ca/search?lr=&as...yAhVO3p4KHR2RAN4Q7Al6BAgJEEs&biw=1455&bih=688 And if you want to experiment to see some for yourself, just buy a bottle of MS70, dip any unc copper coin it and it will turn blue or purple for you.
GDJMSP, posted: "And if you want to experiment to see some for yourself, just buy a bottle of MS70, dip any unc copper coin it and it will turn blue or purple for you" IMO, this experiment will not turn Uncirculated copper coins blue or purple most of the time.
Okay, who's on first? Personally, I do not use MS70. Just my opinion. I enjoyed you question, thanks.
You may have "ruined" a few cents, but had fun learning the results. Hope you keep the coins so they don't ended up in some novices hands and then posted here as an error coin. LOL
Directly under the heating coil of an electric oven (put it on a piece of aluminum foil), heat the oven to 450 degrees F, when it shuts off, remove your cent (don't burn yourself).
Interesting. I have dipped COPPER lincoln cents in a variety of chemicals just to see the results. Was not very interesting and they all went into wrappers and to the bank. AS FOR MS70, Why do you use it? Semper Fi Phil
Fair enough Mike, but the stuff is pretty much infamous for it. And my personal experience is I've never seen one that didn't. And I'm talking about dipping the entire coin in the stuff, not just applying some here and there with a Q-Tip. I will grant ya though there is a lot of room in judging shades of color between blue and purple. In other words if you wanted to call it some other color - OK, works for me.
Fair enough, we have had different results. I can say what you report does not occur every time. The older a red coin is, the more likely it might happen. Unfortunately, a member has revealed something coin doctors do to speed up any chemical reactions that may occur.
Actually, to see if this experiment worked on all coins, I tried it on a red-brown shield zincoln, but it got a bit too hot and melted. First time i saw liquid metal, specifically zinc, in person.
I achieved the purple color on a brown 1971-P. The obverse is worse than the reverse because they were some airborne saliva droplets that landed on the penny. Anyway here are the results: But the obverse showed a color gradient from a dirty orange to a dull purple.
