What makes my Eisenhower look Gritty?

Log in or Sign up to hide this ad.

I'd guess die wear, similar to what happens with the frosted areas of proofs. When the die is new, the coins produced have a blast white frosted look, as the dies wear the frosting diminishes and the coins produced begin to look less white and more polished.

 

I don't know if I am correct, but I think the die strike may be the issue, and possibly combined with some die problems (where the die fields are not really smooth). What I see is that aside from what you are noticing is that 1) there is a lot of md on the lettering, both obverse and reverse, and 2) the edges of the fields (look on the obverse more, could be because it is the hammer die?) looks like it drops off in the middle of the lettering, as if the die was simply polished on an angle so that the full force of the die was not striking the planchet.

But I think that this may simply indicate the hammer die, especially, was not in secure enough or something that caused it to skip or slide as it was striking. Not only giving md on lettering, but also causing the field to not be struck well. Perhaps there was an issue with the pressure used as well for this????

Just ideas, I don't know enough to say for sure that is that, so I am looking for others to comment on this.

 

It's just a late die state (LDS) where the surface of the die no longer has an even frosted or "matte" finish.

Note the tiny bright spots of silver which give it that grainy appearance. The uneven appearance near the edges on the obverse are die sink and is a problem with these large coins.

 

That shiny area below the Bell and Moon may have been caused by a Mint Worker polishing out a Clash of Ike's Portrait on the reverse Die. The pebbley effect on his Cheek was probably due to some metal particles in the Incuse Area leaving their impression in the Die--which then transferred to struck coins. Planchet Preparation also plays a large part in how a coin will look after striking.

 

Regarding die sink problems on the Ike, the Ike group has a page that has this on that (talking about 1971-1972 coins), so presumably the steel issue of the die was taken care of by 1975 or 1976 for this coin (found under Metallurgy of Ike Dollars).:
"However, as hardenable steel, it is very important to know that W-1 does not through-harden. What does that mean? The outer surfaces in contact with the quenching medium will achieve the most martensitic structure and hence the highest hardness, toughness, etc. For example, if one were to cut through a W-1 die, the hardness readings of the steel decreases as one moves towards the center of the die’s cross sectional thickness. This is due to the fact that the inner cross section of metal does not come in direct contact with the quenching media and therefore can‘t quench fast enough to completely transform the soft austenite to martensite. The inner areas end up retaining an austenite phase in the metal matrix. This condition allows for a small degree of plasticity of the die when striking the planchet, and could easily lead to what was known as die-sink.
Die-sink occurs when the dies deform to a very small degree as opposed to remaining completely rigid when contacting the planchet under full pressure. Relatively speaking, the softer inner areas of the die were allowing a fair amount of plasticity of the central die face as compared to remaining rigid as a more through-hardenable tool steel would perform. Die sink from the operating strength of the W-1 tool steel was not allowing the mint to get coins that were fully struck up on the 1971 through July 1972 Ikes, thus necessitating a low relief design for the business strikes. The die sink phenomena lead the mint to search for a better tool steel to strike the large Eisenhower dollars."

.....
But that is not to say that one die, or even a die set could not have a problem that left the inner areas retaining one phase and the outer areas having another. If this is the cause.

Would love to hear more, because it would help me learn more about this.

 

I hope this doesn't sound dumb, but why is there no designation of it being proof or unc?

 

Geek, I know this is a bit off-topic, but did you have to tweak the color of the photo? The reason I ask is that the green beanie looks more blue than green.

Chris

 

I don't know if this will answer your question, but it also says this:

"As you can see, business strike copper-nickel coins are mostly copper in reality. Copper is typically rather soft (ductile) compared to most other metals. The nickel contained in the copper-nickel clad composition adds a degree of hardenability and wear resistance. The silver clad coins themselves contain approximately 60% copper as well. Silver too is ductile by nature, and therefore the silver clad coins were softer than the copper-nickel clad counterparts. This allowed the silver uncirculated and proof coins to be stuck in a higher relief and still maintain crisp details, as the metal “flowed” much more readily into the die cavities."

But in reality, the W-1 they are talking about is the steel used for the die, not the coin planchet. The coin planchet simply is one of two compositions, and depending on which it is, can provide either a better or worse relief. Here's the difference between the two used (same source)
"Metal compositions for Eisenhower dollar planchets were the following:

Copper-Nickel Clad: inner core of copper sandwiched between two outer layers of copper-nickel alloy comprised of 25% nickel and 75% copper. Used for all circulating business strikes and clad proofs.

Silver Clad: inner core of 20% silver and 80% copper alloy sandwiched between two outer layers of 80% silver and 20% copper alloy (± a small tolerance on all percentages given). Popularly known as 40% silver clad. Used for silver uncirculated and silver proof coins."

 

Just curious. Thanks!

Chris

 

The slab is marked MS denoting a business strike. If it were a proof, it would be marked as PR. BTW, there are no dumb questions in numismatics.

 

Keep it and replace it.

 

Personally I kind of like the look, looks like the old matte proofs in a way. Of course if it totally clashes with the look of the set, you may never be happy with it.

 

Upgrade to an MS68.