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 Replies: 8 / Views: 3,184 |
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Moderator
 Canada
10456 Posts |
The term " Struck Through Grease" or " Greaser" is used to describe almost any kind of struck-through error, quite loosely. But what exactly, is the "grease"? This interesting, compressed flake of crud fell out of a 1961 1c sealed mint bag that I recently opened. It certainly looks like compressed grease mixed with "crud", but looking closer, I was surprised to see just how many flakes of bronze were mixed in with this. Unfortunately, I did not find the coin with a matching "struck-through grease" error pattern on it (how cool would that be)? An interesting conversation piece for my error collection, and I thought I would share it here.     "Discovery follows discovery, each both raising and answering questions, each ending a long search, and each providing the new instruments for a new search." -- J. Robert OppenheimerContent of this post is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. See: http://creativecommons.org/licenses...0/deed.en_USMy eBay store
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Pillar of the Community
United States
4618 Posts |
Wow! That's actually kind of neat! I've never found anything like it in my years of collecting. The curve in the mass looks like it may have been shaped by a bolt or screw. I have several "struck through" grease and debris coins that show what looks impressions from possible metal shaving in the grease. It really is too bad you didn't find a coin to match or devices struck into the grease. If you had, you could have had it graded.  What's the weight of the crud? Is it flexible or stiff? Brittle or hard? ANA ID: 3203813 - CONECA ID: N-5637 Clean a coin that may be worth collecting? Please DON'T! When in doubt, leave it dirty!! 
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Bedrock of the Community
United States
94367 Posts |
That's very interesting, thanks!
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Pillar of the Community
 Canada
5585 Posts |
Does the diameter of the "arc" that's in the crud match a cent coin?
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Moderator
 Canada
10456 Posts |
Bill - look again at the first photo. There is a reason why geologists always have a scale on their photos... on my honeymoon, my wife once asked, why are you taking so many pictures of your lens cap or rock hammer? "Discovery follows discovery, each both raising and answering questions, each ending a long search, and each providing the new instruments for a new search." -- J. Robert OppenheimerContent of this post is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. See: http://creativecommons.org/licenses...0/deed.en_USMy eBay store
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Pillar of the Community
Canada
9862 Posts |
Great find!
Will you be analyzing it?
"Dipping" is not considered cleaning...
-from PCGS website
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Moderator
Australia
16810 Posts |
The lubricant or "grease" used on high-temperature, high-pressure modern minting machinery is solid or near-solid at room temperature. The "grease" that fills the die is indeed a mixture of this lubricant and metal dust, and it's rock-hard when cold. I have heard people ask, "How can Grease Fill a die, wouldn't it just all squirt out under that much pressure?". That might indeed happen with normal household grease, but "mint grease" ain't like that. Don't say "infinitely" when you mean "very"; otherwise, you'll have no word left when you want to talk about something really infinite. - C. S. Lewis
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Pillar of the Community
Canada
9862 Posts |
Thanks for that info Sap
"Dipping" is not considered cleaning...
-from PCGS website
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Moderator
Canada
10456 Posts |
Quote:
Will you be analyzing it? Probably not. I am not set up in my own lab for analyzing hydrocarbons. It might have a date with the SEM for some cool photos though. I actually thought about writing an article to Errorscope on the "grease" at the Royal Canadian Mint. I have several errors Struck Through Grease, with some of the grease retained on the coin. "Discovery follows discovery, each both raising and answering questions, each ending a long search, and each providing the new instruments for a new search." -- J. Robert OppenheimerContent of this post is licensed under a Creative Commons Attribution-NonCommercial 3.0 Unported License. See: http://creativecommons.org/licenses...0/deed.en_USMy eBay store
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Replies: 8 / Views: 3,184 |
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Posted 04/19/2020 6:15 pm
