Hi, this is a question regarding an oddly streaky 1936 penny. I scanned it, hopefully my pictures will be ok...the details of the coin are good in person, but don't show well at all in my scans. Is this considered a lamination problem, or something else? Thanks in advance for any responses!
That is about the weirdest wood grained cent I have seen or else your scan has done something to the image. Wood graining is caused when the alloy is not properly mixed and it tones at different rates/colors. How close to the correct color is the coin? BTW, here is what some look like (not my coin).
As a computer professional, I would say that (in other words just a guess) your problem is light reflection from the scanner's lamp! You can try to surround the coin with flat black paper (in other words cut a coin sized hole in the paper) to reduce glare, but it still might not work because the coin has raised edges. The close (raised) surfaces show up correctly, but the hollow part of the coin reflects the light backward, giving the streaked pattern. If you are scanning a coin with lamination, the gloss of the laminate does the same thing! (Gotta be matte finished) Again this is just a guess! Try taking a digital photo of the coin to see if the flash does the same!
Thanks for the responses, I promise you that this is as close to the exact color as when I look at it, just a little more shine in person. No perceivable difference otherwise... any conclusions?
ok here's a couple pictures I just took. one each with flash, and 1 each without flash, seems a bit washed out with the flash...but the other picture (although blurry sorry, does have the right toning
Looks like the coin was stored with something that may have stained the metal, as a distinct pattern shows up. Looking at it, the pattern is linear in appearance, one thick line and then two thinner lines all going the same direction. Reaction to what they were stored in?
That may have caused some of it, but most is the alloy. Look at my avatar or look in this album. Lots of them. http://www.cointalk.com/members/rlm-s-cents/albums/10/. It is hard to tell for sure, but I suspect the larger lines are toning and the finer lines are the alloy mixture.
rlm, thanks for the link...good to know an explanation,for the coloring. So technically, is this an error coin, and if so, under what category?? Thanks
Looked at the link pics! Again, the lines on the pics are still linear, in that they all point the same direction on the coin. Here's an idea! Take the same coin originally posted on the thread. Scan it several times BUT turn and MOVE the coin on the scanner bed. If the line are on the actual coin, they will still be in the same position no matter what direction the coin is turned on the scanner. If the lines are turned on the coin scans you know it's the scanner and the laminate to coin reflections! Also I have found that the position on the scanner bed can make a difference! But to me I find it interesting that the stains are not random. (If say I splatter a coin with a reactant, like say ammonia or chlorine, the reaction would show up as a random spatter pattern). The only way it would be linear is if I brushed the agent on. Hope I'm making what I'm thinking understandable? Is there a possibility of removing the coin and cleaning it? It could be that the coin was stored in a holder made of leather and the tanning fluid reacted to the metal? Lots of ideas hitting my head here! Several of the photos show streaking in straight lines on different angles per coin. One at the bottom shows like the coin was held at the edge and dipped? http://www.cointalk.com/members/rlm-s-cents/albums/10/137/ It also could be that the coins are tarnishing evenly except where an agent is protecting the metal somewhat? Just theorizing here! What would cause an alloy to mix in a linear pattern? (versus circular) What they use as an alloy for these coins were 95% copper and the rest was tin and zinc. PURE copper work hardens (starts out soft. then as it's bent it becomes stiff!) so I am wondering if there's a test for different oxidation properties for the different metals? Darker streaks copper and the lighter for the tin/zinc? I am looking at my 1936 penny, and with a flashlight at an angle, the raised surfaces (like ole Abe) is tarnished darker than the flats! Dead on though shows just a tarnished copper color, NO streaking!
I have never heard it called an error, but I suppose..... If anything, I would call it a planchet flaw
The linear pattern is due to the sheet metal preparation. It is rolled. This causes nearly all the elongation to be in one direction. Thus the blobs all become ellipses with their axis in the same direction. Also, I am pretty sure the lighter color is brass (higher tin/zinc) and, yes, that can easily be determined with X-Ray Spectrophotometry.
Killer! Like your explanation! Sounds reasonable with the rolled sheets. The rolling stretched the metals, and the copper would react differently than the brass because it is softer? Also this would be indicative of the metals not alloying right?
