Question about indian head co/fe #s

[robertj298]

I've noticed that most of the indian heads I find have a co # of 34-37 and most of the wheat pennies have a co # of 41-42 but a lot of times when I find a wheat penny that has turned green the co # will be the same as an indian head. I'm wondering if anyone has ever found an indian head that hasn't turned green and if the co # is still in the 34-37 range or if it would match the 41-42 co # of the wheat pennies?

 

[shawnIN]

A lot of the Indians I have dug from the field I have Been hitting have been from the low 20's on up through the upper 20's. I was told fattys come in the low 20's. almost all of them have had major corrosion from being in the field for over a 100 years. I have learned to go by sound. If it sounds good and the conductive number is good, I dig it. But that is just me. The results have been pretty good, but farm field hunting is a little easier to dig in. Once I start hunting parks and yards, my digging may change.

 

[NebTrac]

There are times when I get a wheat that comes in on the high end of an IH #. Almost always they have been earlier wheat, older than 1920 and most of 'em have been like 1909, '10, '12....the earlier ones. I just figured they were using or blending some of the IH metal in at the mint. Just a hunch.

NebTrac

 

[robertj298]

I guess what I'm really trying to figure out is if the co #s are different because of the copper content or are they different because of the green patina that all indian heads have after being in the ground so long.

 

[moonshine]

id say its the metal composition and quantity. ever notice how an old worn out coin will read lower (CO number) than a "newer" one?



quoted from here: http://coinspecifications.com/category/cents/page/2/

 

[Goes4ever]

According to your link, and I have read it many times the penny had the exact composition from 1864 to 1962. Both say they are 95% copper and 5% tin and zinc

I simply do not believe this. How can this be true when indians clearly register different than wheats?

And even more you can almost always tell if you got an early wheat or a newer wheat by the signal it gives. 40-50s wheats always are higher co number than older 30s and earlier wheats.

So i smply do NOT believe the stats of metal composition the US mint has put out there

 

[moonshine]

I totally agree with you. it can not be the same from 1864 to 1962, you know your penny numbers, the link says there were different compositions. i think what it is, is that there is a difference in how much tin and zinc was used to turn the copper into bronze. what i meant to point out in that quote is them saying there were the different compositions of metals used to make the bronze. maybe they meant the steel 43 cents, i dont know.

i also think its interesting that they say it like this:

95% copper
5% tin and zinc

(OK, so how much tin and how much zinc???, 1% of that is tin, and 99% zinc? 50/50?)

I cant seem to find any real information either. maybe we need to send some coins off to be melted down and analyzed.

 

[robertj298]

Anyone ever take a reading on an Indian head that hasn't been buried and doesn't have the green patina?

 

[Goes4ever]

Anyone ever take a reading on an Indian head that hasn't been buried and doesn't have the green patina?

yes I have and for me they read the same as a buried one

 

[Johnnyanglo]

For comparison, here is a chart of the Co values for the penny.

[attachment 264269 PennyFlatVs.EdgeE-TracCoValues.JPG]


The on-edge Co values are always higher than the same coin parallel to the coil.

The 1887 Indian Head was composed of a mixture of 88% Cu and 12% Ni. It has the lowest Co reading.
The 1909 Indian Head was composed of a mixture of 95% Cu and 5% Zn/Sn.
The 1911, 1937, 1942 Wheats were composed of a mixture of the same 95% Cu and 5% Zn/Sn
The 1946, 1947, 1952 post-war Wheats were composed of the same 95% Cu and 5% Zn/Sn
The 1962 Memorial was composed of either 95% Cu and 5% Zn/Sn (or 5% Zn alone)
The 1970, 1975 Memorial was composed of 95% Cu and 5% Zn
The 1982 Memorial was composed of 95% Cu and 5% Zn (some may not be)
The 1983, 1984, 2011 Memorial was composed of 99.2% Zn core with plated layer of 0.8% copper

Even though the 1909 Indian Head composition is supposed to be the same as later coins it definitely does not react in the same manner.
It looks like after WWII, the composition settled down until 1982 when the coin composition changed.

While not a scientific test, the data indicates that coin composition was probably adjusted depending upon the availability
of Zinc (Zn) and Tin (Sn). I'm sure no one at the US mints cared much if the exact recipe was adjusted for the penny. Even more likely
that the early Indian Penny was subject to more variations in composition when standards were probably less stringent.