Mint Director explains cause of cracked planchet coins 0

[Errorists]

Can't improper alloying of metals cause such blisters? Also, what does the reverse of the 1921 Morgan look like?

Edited February 9 by Errorists

[RWB]

On 2/9/2024 at 7:15 AM, Errorists said:

Can't improper alloying of metals cause such blisters? Also, what does the reverse of the 1921 Morgan look like?

Possible, but very unlikely to avoid detection during melting, ingot casting, rolling and annealing, plus the routine assays made along the way to cutting blanks. Further, most collectors do not realize that silver ingots, and to a lesser extent strips rolled from them, have inconsistencies in fineness between center and edges. This is called "silver segregation" and is described, along with details of the above, in my book From Mine to Mint.

[Henri Charriere]

Silver segregation, eh?  Is that a polite way of suggesting the presence of non-silver contaminants?  Makes one wonder what additional refining method is used to help .999 silver attain .9999 fineness.  🤔 

[Errorists]

On 2/9/2024 at 8:01 AM, RWB said:

Possible, but very unlikely to avoid detection during melting, ingot casting, rolling and annealing, plus the routine assays made along the way to cutting blanks. Further, most collectors do not realize that silver ingots, and to a lesser extent strips rolled from them, have inconsistencies in fineness between center and edges. This is called "silver segregation" and is described, along with details of the above, in my book From Mine to Mint.

I'd rather have Mint To Mine pockets. I guess there are inconsistencies otherwise we wouldn't have such coins. I see many lamination errors in the wartime nickels. Perhaps alloy mix wasn't just right. 

[RWB]

On 2/9/2024 at 3:05 PM, Errorists said:

I see many lamination errors in the wartime nickels. Perhaps alloy mix wasn't just right. 

The war nickel alloy is a completely different critter. Mint operatives knew it was a "bad" alloy and difficult to roll without cracking and splitting. Plus copper, silver and manganese do not form a true alloy -- only an unstable mixture. "Whiskers" of Mn are commonly seen when these nickels are broken.

[Henri Charriere]

On 2/9/2024 at 5:51 PM, RWB said:

The war nickel alloy is a completely different critter. Mint operatives knew it was a "bad" alloy and difficult to roll without cracking and splitting. Plus copper, silver and manganese do not form a true alloy -- only an unstable mixture. "Whiskers" of Mn are commonly seen when these nickels are broken.

Would "whiskers" be observed if a Sacagawea dollar were "broken"?  Different composition -- no silver -- and less than half the manganese of the war nickel:  only 3-1/2% to the war nickel's 9% or is silver key to the phenomenon?

[RWB]

On 2/9/2024 at 6:37 PM, Henri Charriere said:

Would "whiskers" be observed if a Sacagawea dollar were "broken"?  Different composition -- no silver -- and less than half the manganese of the war nickel:  only 3-1/2% to the war nickel's 9% or is silver key to the phenomenon?

I don't know. Have not paid much attention to Manganese Brass alloys.

[GoldFinger1969]

Appears "gold segregation" with gold coins and Saints/Libertys is not as big a problem, I take it ?  Gold and copper must mix pretty well ?

[Henri Charriere]

On 2/10/2024 at 9:28 AM, RWB said:

I don't know. Have not paid much attention to Manganese Brass alloys.

Respectfully, wrong answer.  You should have said you don't know because you haven't broken one yet.  

[RWB]

Copper and manganese alloy OK, but adding silver creates the bad alloy situation. (I broke one several years ago to get change for a gumball machine -- does that count?)

[Henri Charriere]

On 2/10/2024 at 1:39 PM, RWB said:

Copper and manganese alloy OK, but adding silver creates the bad alloy situation. (I broke one several years ago to get change for a gumball machine -- does that count?)

Anything that saves me the trouble of doing something like that, in the interests of research and contributing to the "body of knowledge" in numismatics, counts, it goes without saying.     🤣