Die polish

Looking at my 1/10 oz fractional buffalo (uncirculated) I ordered from the mint under a 16x loupe, I can't seem to find any die polish. I looked in the recess of the design and through the letters, with no luck. The apperance of the coin has an interesting texture, almost grainy like it was a burnished uncirculated coin.

How come it is hard to find die polish on it?

 

Log in or Sign up to hide this ad.

The die had not needed polishing yet?

The die had not needed polishing yet?

 

But aren't all dies polished before coins are struck?

 

Yes but to a mirror finish - die polishing that one can see

Yes but to a mirror finish - die polishing that one can see or detect is generally only referred to when they remove a die already in service and polish it to extend the life or correct a clash.
New dies (esp. on this type coin) are poilshed to a point where it's not able to be seen at all - I would not expect to find die polishing marks on your coin under any circumstances except maybe under a microscope.

 

This is often true... but has not always been true for all coins.

In the thread "your old proofs", take a look at two coins I posted - the Pattern 50c 1859 J-242 PR65RB and the 1/2cent 1855 PR62BR.

Both those coins show very fine parallel lines raised above the fields. Of those two issues, all known coins show those same characteristics; it is clear those lines are a die characteristic. Since "raised on the coin" means incuse on the die, it seems clear those are die polish lines.

Apparently, 1850s die polishing techniques were nowhere near where they are today. No surprise, really.

 

Very interesting! I had no idea, I have alot to learn. Thanks all

 

These are known as or often called "die flow lines."

 

Really?

So the lines on this coin are die wear / metal flow?



(Inside the rays to the left of Lady Liberty)

And this one:



(To the right of Liberty's bust)

I couldn't disagree more.... Those are die polish caused by die lapping, not die flow/wear.

 

IMO, there are die polish lines and there are die flow lines. They are quite different but similar looking phenomenon.

Die flow lines extend radially on the coin -- they are caused by die wear.

Die polish tends are most often in a roughly vertical or horizontal direction but can be in any direction and sometimes even in a number of directions -- they are caused by manipulation/polishing of the die during preparation and/or lapping.

Die polish is much more common on older coins. I'm not sure what they changed, I suspect two things are at play: 1) they just used to use dies much longer in the old days and therefore were more likely to polish/lap them to increase their life, and 2) modern polishing techniques don't leave polish lines like the old technique.

Respectfully...Mike

 

Ok, so looking at my PCGS (former ANACs slab) AU58 $5 1908 indian head under a 16x loupe, I immediately go to the neck area. I don't see toolmarks, but what appears to be a dozen or so horizontal, fine lines. Barely visible. Is this die flow lines or die polish?

Confusing...

 

I'm sorry, I don't know the series well enough to even guess. If it were a large cent, it would be another story...but with incuse gold my head starts to spin.

Do you have a high-resolution photo of the feature?

 

I have 2 photo's I took when I had my Digital Blue Microscope up and running, I have to set it up on another computer, don't have the space to do it in this house. Here are 2 photo's I took, although they aren't in the same area of the coin. I'm sure the coin is genuine, I just want to know what I'm seeing.

 

GCL, That looks like die flow in the pics. However, I would check with a specialist in the series to be sure.

 

In Kevins pictures the top one does show a polish lines (and a few flowlines), the bottom one shows mainly flowlines but there is one polish line just a little above the center of the picture.

 

I noticed that too. So, in short, what I've made from my observations. Die polish lines go through the field and ON the devices, where flow lines are only in the recessed areas and do not go on the devices? Is this correct?

 

Err, I think I was confused. I think I know why now In the coin in question, the design is 'incuse', and it looks to have die polish on the 'raised' part of the coin (the devices), but since the design is incuse, these are actually the fields! (lowest part of the coin)

The fields of the coin are the highest point here. I think this is right?