Die Grease during minting process?

[wdrob]

 

I have seen examples, and it has been explained to me, how certain irregularities on some coins are due to die grease. A good example is the post that MY13EAGLES posted questioning the lack of a 'L' in LIBERTY.

 

I am curious as to how a coin should be viewed and graded if the obverse of the coin has full cartwheel luster and the reverse luster is subdued due to die grease (that is what I am told is the cause) yet still has mint luster.

 

I ask this question based on the characterization of a MS70 for example. It is described to be "as minted". I would surmise from that line of reasoning that the coin in question was "as minted" and therefore should be taken into consideration when grading.

 

The example in question

 

 

 

Thanks,

Bill

 

 

[Deerefan8420]

Bill, I don't see anything on this coin that would resemble the signs of a grease-filled die(I could be wrong though). If you are referring to the discolorations/dark streak between 6 and 12, I'm not sure what would cause that. What's going on with that Mint mark though? Is that an O over CC?

[wdrob]

 

Yes it is a 1900-O C/C

 

The coin does not look like one that has lost luster due to dipping as the obverse is completely unaffected. I just saw another coin similar in appearance on the VAM World Wiki and asked about it and from what I gathered, that was the reason it looks like it does. It is not as if it is toned on one side.

 

And yes that area as well as from about 4 o'clock to almost 1 o'clock that is mainly affected.

 

 

[Keigwin]

Grease on a die is usually a hard blob, mixed with dirt, dust, and metallic particles and compressed from striking. It fills die voids and results in shallow or absent devices on the coins it strikes.

 

I don't see any evidence on this coin. I see a stain.

 

Is it raw? Has it been dipped in acetone? That won't remove the stain (nothing will, in all likelihood). But if there's some organic film on the coin acetone would help.

 

It's really hard to say what might have diminished the reverse luster, assuming it was once strong.

Lance.

[wdrob]

Grease on a die is usually a hard blob, mixed with dirt, dust, and metallic particles and compressed from striking. It fills die voids and results in shallow or absent devices on the coins it strikes.

 

I don't see any evidence on this coin. I see a stain.

 

Is it raw? Has it been dipped in acetone? That won't remove the stain (nothing will, in all likelihood). But if there's some organic film on the coin acetone would help.

 

It's really hard to say what might have diminished the reverse luster, assuming it was once strong.

Lance.

 

It is slabbed in a MS62 ICG slab that I felt was under graded since the obverse and reverse are somewhat free of bagmarks in both the fields and device. The obverse luster is very high.

 

I can't imagine someone applying an acid to only the reverse so I have ruled that out (imo) and as far as it being a stain, how might a coin develop such a stain and from what source might you guess? It sounds feasible but hard to understand how it could not be removed.

 

I am tempted to crack it out if I knew it was something that could be corrected by conservation. PCGS will attempt to cross with it still in the current slab and if it would not meet the current grade or higher they will leave it in the holder and send it back. I don't know why NGC won't do that?

 

 

Here is the whole coin

 

 

 

 

 

 

[Keigwin]

It looks like a nice Morgan and a cool one at that. MS62 feels a little low. Unless impaired luster was the culprit.

 

NGC won't cross anything other than PCGS coins. It's just their policy now. So if you want an NGC slab you'll have to crack it and risk the BB.

 

You can try a cross at PCGS...nothing risked except fees and S/I. If you must have it in PCGS plastic then it is best to cross at "any" grade. I wouldn't crack anything I wasn't sure would grade cleanly.

 

Coins sometimes get stains. Who knows why or what has been done to them. I've just found that once stained, it's usually permanent. Even an acid dip like eZest (nee Jeweluster) won't remove it.

 

Of course it could be something other than a stain. Something organic that might be removed with acetone.

 

Tough choices. If you decide on NGC then you might as well crack it yourself and bathe it in acetone. Might do the trick. If no change, then pick either TPG and cross your fingers.

 

If your reasons for NGC or PCGS grading aren't strong, just leave it alone. Sometimes small problems make it hard to enjoy the coin. In that case sell it and look for another already graded.

Lance.

[wdrob]

I appreciate the info Lance.

 

I think I will just leave it be for now and if I am never able to sell it then I might send it to PCGS for a try since I also think it is MS63 even with slightly muted lusted because of what may indeed be a stain. The obverse luster does not appear to be impaired at all.

 

I will pass on cracking it and NCS though. The more I think about that option the less desirable it becomes.

 

 

 

[coinman1794]

Grease very frequently contaminates coins, in a number of ways. Sometimes a thin puddle of grease can be struck into the surface; this is the cause of most milk spotting on 20th century silver coins.

 

What you have looks more like discoloration of planchet impurities, rather than struck-in grease.

[Conder101]

I'm not an expert on Morgans,but I believe the O/CC dies were reworked many years after they were originally produced for the CC mint. They probably suffered from some rusting and would probably have undergone some grinding and possibly even a reannealing and rehardening. These were not "pristene"new dies, so I would not be surprised if these coins normally come with subdued luster on the reverse. I doubt if the subdued luster is from a grease strike through.

[mhomei]

Hey Bill

here is a clasic example of grease filled die

they also come bigger and smaller and at any point on the coin this particular one has two grease filled areas

by the way that is a cool o/cc

[img[/img]

[wdrob]

 

Thanks for all the opinions and advice on this coin. I think I will stray away from my assumption of grease as there have been some very compelling points made and I think Conder may have nailed it as from what I have read as well, states that these dies were reworked in Philadelphia nearly 10 years after the closing of the Carson City branch.

 

Based on that assumption one would think that it would be taken into consideration when grading a coin such as this, where the lack of bagmarks on both sides and an obverse with full original mint luster, more closely resembling that of a 63 or 64, should not necessarily be penalized for something that was "as minted".

 

I think that an opinion from those closer to the mind of current grading practices would be the determining factor of whether I were to resubmit since I really do think it is a candidate for a much better grade by at least one point.

 

Once again thanks for getting me past that grease theory.

 

Bill

 

[RWB]

The depressions in dies can become clogged (this is the mint’s term) due to buildup and compaction of metal dust and the light oil used to lubricate planchets. Under certain conditions, this can occur within a hundred strikes or less, as was noted during testing of zinc coated steel planchets in 1942-43. Relief details can become blurred or totally obscured depending on the extent and length of time the clog remains. A clog was (and still is) removed by cleaning the die with a brass wire brush while the die remains in the press. In severe cases, the die had to be removed for cleaning by the die sinkers. The only effect clogging has on the field is to soften sharp flow lines. Since these are the primary creators of “luster,” clogging could reduce localized luster.

 

1900 O/CC coins do not show evidence of rust or rust removal. Working dies were coated with oil or wax until they were needed.

 

As far as grading - a coin straight from the dies, would be MS 70 --- regardless of appearance. The other approach is to assume that MS 70 equals a perfect coin that is complete and flawless in all respects. By that interpretation, one would have to know details of the master die that are unknownable; thus a MS 70 coin cannot exist. (The whole MS stuff from Sheldon is a bunch of krap, in my opinion.)

[wdrob]

 

The depressions in dies can become clogged (this is the mint’s term) due to buildup and compaction of metal dust and the light oil used to lubricate planchets.

 

The only effect clogging has on the field is to soften sharp flow lines. Since these are the primary creators of “luster,” clogging could reduce localized luster.

 

Busted!

 

I guess I would have been privy to that info if I had already bought your book "From Mine to Mint" ..

 

That is what describes it well. It is almost as if graphite were embedded in the various darkened areas and the lighter areas still maintain mint luster.

 

I just ordered myself a Christmas Gift from Wizard (the above mentioned) so that should help in the future.

 

 

 

 

[RWB]

"It is almost as if graphite were embedded..."

 

That's a good observation, and metal dust will look much like that.

 

Details about the 1942-43 experiments are in the book "Pattern and Experimental Pieces of WW-II." This is about the plastic and metal coinage experiments.

[coinman1794]

 

Based on that assumption one would think that it would be taken into consideration when grading a coin such as this, where the lack of bagmarks on both sides and an obverse with full original mint luster, more closely resembling that of a 63 or 64, should not necessarily be penalized for something that was "as minted".

 

...

 

Once again thanks for getting me past that grease theory.

 

Bill

 

Your coin still has a dark streak of either grease, planchet impurities, metal dust and grease, or toning; and it is likely to be taken into consideration by the graders.