Insider

Don't over think this. What could cause a mark into the surface of a struck coin. Never mind. This mark could be: 1. PMD. 2. A strike thru 3. A planchet flaw 4. Corrosion 5. Other... Answer Tuesday. Happy Holiday.

Yes, very commonly! One of the things I mentioned (PMD) is on 20% -30% of the coins I see each day. You know what, I'm reaching the end of my attempt to revive this place. Members (less than 2 dozen active?) wish to comment OFF SUBJECT for what ever the reason. Insecurity? Anyway, I'm not going to give up just yet. Now, rather than bla, bla, bla does anyone care to post the other POSSIBLE things these marks could be.

What are the things that could commonly cause this mark on a coin? 1. PMD 2. 3. 4.

Good post. 1. Parallel 2. Relatively long 3. INTO the surface with uniform depth 4. Rough interior What are some of the things that can happen to a coin to produce these characteristics? Four come quickly to mind. There may be others if I think about it. Keep it simple because it is.

Before trying to ID the cause of anything you see on a coin a person needs to be able to describe it in words that someone who cannot see the coin will understand and imagine what it looks like. Great example so far: Parallel marks. What else? Are they wide/narrow, short/long, smooth/rough, jagged, raised, deep/shallow, colorful, etc.

NO. Not even close. Would someone care to describe what they see?

This is a Standing Liberty quarter. The marks you see are commonly found on silver coins. What do you think caused them. For those who need to see the entire coin:

Posting is fun. I use color, bold, CAPS, and size to help make my ideas clear. I don't police what others do. What they post is more important to me than how they post. I'm a five year old rookie poster. During that time, I've learned that folks of every background, sex (now there are at least 20!), and intelligence level post on the Internet. Some of our foreign members may not understand English. We are all lucky to be welcomed here by NGC. I don't usually go with the flow and hate most rules so eventually I may be banned. Anyway, I think there is a way to block a member who often POSTS IN CAPS .

If the stippling is low on the finished disk, where is it on the die? A. On the low part of the die where polishing is last to reach. B. On the high part of the die that is polished out first?

Agree 100%. As the saying goes, ignorance is bliss. Example: When I was young I didn't give a second thought to what was going on in our country. Alfred E. Neuman ("What me worry?") was my twin.

Sigh, Actually, I'm not. Remember my reference to the fellow who took the donkey to the water but the donkey didn't drink. He made sure that his donkey didn't die of thirst. He cupped his hands and brought water up to the dumb beast to drink. I'm a nice guy too (very deep down). Here is the opening paragraph of something you may wish to read so that you become more informed. From Numismatic News: No Flaw Can Hide To introduce the subject of this column, let me quote from a recent article in Road & Track magazine about one of the fastest, most powerful and expensive supercars on earth built by Bugatti: "The final step for each newly assembled Chiron is a painstaking examination under 100 fluorescent lights. NO FLAW CAN HIDE." I'll let you have the last word. I'm out of water and I'm drying my hands. . Next quiz coming soon.

Thanks,I thought I was color blind too!

I don't need to propose anything. I don't know how a toilet works but I know how to flush away any . Try this experiment. Put on the darkest sunglasses you can find and stare at the sun for a few seconds. Remove the glasses, and you will be able to read your drivers license. Now, stare at the sun for a few seconds and then try to read your drivers license. The glare of 100Ws reflecting from the surface of a brilliant white coin affects your eyes and HIDES THINGS on the coin's surface. Florescent light eliminates the glare. Now you can see them.

I don't get emotional over coins. I do get very emotional over the opinions of "ex-perts." I'll expand on what I posted. I have NEVER SEEN a business strike coin from brand new dies that looks anything close to even the last strike of a Special Mint Set cent. Furthermore, I'm sick and tired of the TPGS calling so many coins "specimens," but in this case, I'm with them. So, IMO, something was done to the dies that made these coins different. A prototype finish as a test for the proposed (?) future SMS coins makes the most sense. Mrs. Adams was no dummy. Apparently, she did the same thing as some of her predecessors and saved some souvenirs. Furthermore, I like to suggest members ignore this statement: "...different in appearance" demands a "difference in production" - the two are not linked." As we all should know (I read From Mine to Mint), the production of a coin involves the settings on a coin press, the preparation of the planchet, and the preparation of a die. These THREE THINGS are linked because anything done to either of these parts needed to produce a coin will change the appearance of the finished product! Thus, while we were not around to see something made its appearance will offer clues.

Thanks for posting the poop. IMO, the only thing relevant to the thread is your call to save incandescent bulbs. Good Luck. As for florescent lighting used for coin exam, I'll post this v.short version of a true story: Famous authority on particular coin series comes to PCI table at major show with MS-66 blazing white gem he just bought. I looked at the coin in florescent light and told him it was an AU. Then I brought him behind the table to look for himself. He agreed. That night, he bought a florescent light to use the next day. Folks who know what they are talking about are the ones worth listening to. That is not self-promotion, it's a fact. .

You can lead a donkey to water but...

Copper metal has certain shades but silver-gray is not one of them. Usually, it indicates the coin should be authenticated as electrotypes and copper plated base metal counterfeits can both show this characteristic. When you see this color, the first thing to check is if it is on the surface or into the surface. What could cause it? 1. Very rarely, paint or a surface residue. 2. More commonly some type of plating. Some of you have had this happen w/o electricity when you put a copper coin into some very old dip. 3. Rarely, contact w/solder. That was the case in the OP. The gray color was on the surface. Nevertheless, someone wanted to make sure the coin was genuine and drilled into its surface. 4. Counterfeits that have a base metal core as in the second image will show the gray color in places where the copper surface has been worn away, pealed off or damaged. Did any of you see the deep scratch along the relief of the coin in the OP?

Unable to post any "likes" for RBW's posts. Interesting topic.

PVC damage + altered image just for you.

One BIG difference with this forum and another forum (besides the lack of traffic except for a half dozen posters) is this: Some numismatists here (who could add a lot to our discussions) RIGHTFULLY complain about things like poor images; yet cannot be bothered to respond to a simple question. IMHO, it would be more useful for all of us if they would go back to writing/research or talking a walk. Forums are not a popularity contest. If folks have not guessed that I am not here to make friends, I'll say it now. I'm not here to make friends or enhance /ruin my reputation. The ONLY reason I'm posting here so much is I'm banned from one more active and I'm making an attempt to get this lame site used by more than a very few posters + I like to argue, bait, tease, frustrate, ruffle, ... As for florescent light... folks need to get educated. An article was just published in Numismatic News. Check it out: Florescent Light: No Flaw can hide.

How about posting some tips here! Agree! But better than this:

Quiz answer tonight.

Thank you. Read the post from Physics-fan. He covered much of it. BTW, do you see a number in the circle of dots I posted? I've been told that this particular circle of color is one of the most commonly missed in the usual test. Apparently, more women are colorblind than men. This one also gives lots of folks trouble.

I'm providing this image for our visually impaired members. What number do you see?

Very sad. I though a numismatist of your stature would add something useful as this poster has: "The pic on the nose almost looks like its a lead core with copper plating which is faking off. Unusual, unless its a rare date and an old counterfeit. The first pics looked like lead encrustations. However, the details here look soft and mushy." So far, we have a copper coin with green/black corrosion spots and areas of gray, The image in the OP is fuzzy and out of focus. That makes it almost impossible to tell if the color change to gray is on the copper surface or under it. My second image is sharp. A member saw a silver-gray color where the copper surface flaked off. Since the quiz is about the change of color and what it might indicate, the authentically of the coins that I imaged is not important. What is important is being able to see a different color on a coin. Then we can see why it is there. So, what could cause a silver-gray color on a copper coin? There are two main reasons and both have been express by one member. Now, be a detective and explain the thought process for us that he may have gone through. Physics-fan can answer later if he wishes but hopefully a few others will try first.