Laboratory Testing & General Mineral Processing Engineering

Laboratory Testing & General Mineral Processing Engineering

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Explanation for potential remnants of marks on layered US Mint silver ingot from 1942 and its primat ... (6 replies)

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4 weeks ago
sbs 4 weeks ago

About 50 years ago I obtained a cast US  Mint silver ingot.  The Mint had a program that permitted the public to exchange silver scrap for ingots. The ingot is noted by its serial number on a US Mint Services Deposit Memorandum and Bar Delivery Receipt dated December 22, 1942.

Most other ingots that I've seen have relatively clean surfaces; however, this one appears to have been the product of a series of several pours of molten silver forming layers after preceding pours had cooled based upon the side edges of the ingot, which are irregular.

The bold hallmarks (eagle, bar number 989, 999.75 fine, 6.04 OZs.) were obviously intentionally added once the Mint finished pouring the total weight into a mold.  It is the appearance of what may be a number of additional faint marks on the sides and the form of the ingot that are perplexing. 

On the right edge there appear to be what may be bubble holes through which gas escaped.  I don't think these holes resulted from drilling but would like to know about them. In the upper third of this side appears potentially the number 3, and to the left of the holes appears potentially a 2 or 7, and further down possibly a 5.

The pinkish-orange image of the left side appears to have numerous faintly stamped numbers. In the center of the left side appear to be faintly stamped and distorted, 4  5  7 2, and about half way up the right corner edge additional potential symbols.  The lower left corner was clipped and may have some mark applied.  Perhaps these were not punched and it is my imagination.   I am wondering if perhaps the side would have been numbered with a pour lot number at various times, and due to the addition of molten silver, previously added pour lot numbers were distorted or nearly totally melted away, leaving only faint partial impressions.   There does not appear to be a final pour or lot number punched in the edges.

The top of the bar has two indentations on the left and the right of the lower of those appears to possibly have been punched a 6 or 9 over a 2 or 7 and toward the top of the photo nearly along the right edge a 2.

I wonder if these potential figures are the remnants of markings made a various stages that were distorted or mostly eliminated by subsequent additions of molten silver in building up the bar to its final weight, or if they may have come about otherwise, or if they are not remnants of punches but figments of imagination.   The Mint Services Memo shows deposit of over 200 Oz of silverware scrap and the return of about 3 dozen 5 ounce class bars of weights just over 4 ounces to just under 7 ounces, all poured in a 5 ounce size mold.

Finally, it is my understanding that the Mint would re-melt assay chips to be cast into bars, and perhaps this bar is an amalgamation of various clippings from other bars that may have had markings that somehow survived recasting though I would not think the marked areas of existing bars would have been clipped away.  Also the Mint refined existing coin stock that was worn or defective in addition to silver scrap that may have had markings.  Perhaps the workers were bored and just toyed around applying random stamps?   It would be interesting to know what the procedure and method for marking bars was, and whether previous punch marks could survive the addition of molten metal.

Fred Holabird wrote a numismatic article years ago describing an unusual cube shaped ingot that was felt to be the product of a dozen or more layers.   Any explanation of the appearance of the various markings and configuration of the ingot would be appreciated.   I've attempted to add the 6 surface images but if only 1 is possible I can attempt to combine them into a single image and repost or add the others.

Thanks in advance ! SBS

 

 

989 RE
https://www.911metallurgist.com/wp-content/uploads/2022/05/989-RE-scaled.jpg
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4 weeks ago
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1st image is right side with holes.  2nd image is left side in pink-orange.

989 LE 754
https://www.911metallurgist.com/wp-content/uploads/2022/05/989-LE-754-scaled.jpg
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3rd image is face of ingot.

989 Obv
https://www.911metallurgist.com/wp-content/uploads/2022/05/989-Obv-scaled.jpg
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4 weeks ago
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4th image is back side.

989 Rev
https://www.911metallurgist.com/wp-content/uploads/2022/05/989-Rev-scaled.jpg
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4 weeks ago
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5th image is top side.

989 Top
https://www.911metallurgist.com/wp-content/uploads/2022/05/989-Top.jpg
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4 weeks ago
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6th image is bottom side.

989 Bot
https://www.911metallurgist.com/wp-content/uploads/2022/05/989-Bot.jpg
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4 weeks ago
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Thanks for any insight or possibly suggestion of a way to examine the bar differently to gain a fuller appreciation of its appearance.

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