Grading my coins

Zach,

Luster isn't created by any irregularities imparted from the die to the surface of the coin. Luster is created from the metal flowing outward through the fields toward the rim along the surface of the die. If you examine a fully lustrous coin under a microscope, you can actually see how the metal flowed. This is why you can see the luster radiate around the coin like the spokes of a wheel when you tilt the coin back and forth under a light.

Take a look at the photo of the Morgan star. You can see the streaks from the metal flow through the fields. You can also see how the light reflects off of the peaks and valleys of the metal flow. Note that you don't see the metal flow through the device, itself. That's because the metal is actually flowing upward (or downward) into the device.

Chris

 

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Chris, I guess I worded that incorrectly, I meant irregularities of the die create the 'flow lines' you mentioned.

 

No, there are no irregularities. The obverse & reverse dies and the retaining collar merely dictate where the metal can flow.

Chris

 

I cannot find where I originally read the definition, but this one is very similar.

[QUOTE/] Mint luster is formed during the minting process. The surface of the die that strikes a planchet has slight irregularities When the die strikes a blank planchet, metal flows into the recesses of the die and outward toward the rim. The irregularities in the die are reproduced on the surface of the coin, Moreover, the flowing metal the surface of the die with faint lines called flow lines. These flow lines become more pronounced as the die is used. The flow lines cause the formation of dials on the surface of the coin which fan out from the center and are most visible near the edge but are also visible near the raised design, letters, and date. The irregularities transferred from the die as well as the radials are readily observed under a microscope. The radials appear as tiny ridges and valleys When light strikes the surface of the coin; the Irregularities and radials, giving a soft diffuse appearance to tone coin's surface reflect it in all directions. This appearance is sometimes referred to as mint frost. [/QUOTE]

 

[/QUOTE]

Just out of curiosity, what is the source of that quote?

Chris

 

Just out of curiosity, what is the source of that quote?

Chris[/QUOTE]

You caught me LOL http://reviews.ebay.com/The-Meaning-Of-Mint-Luster?ugid=10000000001433485

The first one I read, the similar one, came from an actual coin site.... If I could only remember.

 

You caught me LOL http://reviews.ebay.com/The-Meaning-Of-Mint-Luster?ugid=10000000001433485

The first one I read, the similar one, came from an actual coin site.... If I could only remember.[/QUOTE]

I'm not trying to put you on the spot. I'm just curious. If you wanted me to tell you the source of my information, I couldn't. This is how it was explained to me many years ago by a regular customer of mine at the bar. He had a degree in metallurgy and was retired from the Philadelphia Mint.

He's the person who gave me these coins for which he made the counterstamps.

Chris

 

Okay,

Second grading attempt.
The grading of my 1862 Indian Head
(picture is not verry good, hope you can do something with it)

[FONT=Verdana, sans-serif]#: IH1[/FONT]
[FONT=Verdana, sans-serif]Coin:Indian Head One Cent[/FONT]
[FONT=Verdana, sans-serif]Date: 1862
[/FONT]
[FONT=Verdana, sans-serif]Metal: 95% Copper 5% Tin and Zinck
[/FONT]Size: 19mm
[FONT=Verdana, sans-serif]Weight: (no scale yet)[/FONT]


[FONT=Verdana, sans-serif]A.N.ACondition / Grade: Waiting for the book
[/FONT]P.C.G.S.Condition / Grade: F15 (graded with PCGS Photograde online

Picture:


Why F15:
Front:
-The detail in the feathers is not so clear anymore
-Little bit worn off tekst: United (Un) and 1862 (1)

Back:
-Details of the wreath are a bit blurry
-Details of the shild are a bit blurry

 

Great explanation Chris. I would be more generic in my description of luster as the resolidified metal that was melted in the striking process. I do not think generically is HAS to include flow lines, though that is probably a requirement of modern coin striking methods. I say this generically since ancient coins have luster, but not always outward flow lines depending on how it was minted. However, the act of striking a coin always creates a thin layer of melted metal than when it cools forms a shiny covering over the coin. This aspect of coinage was famously used by the Romans to take low grade silver planchets, leech the copper from the surface, and when struck the silver ions on the surface would melt and coat the coin with a silver color. This gave the appearance, fresh from the mint, of a silver coin when in fact it was only about 5% silver.

I know, ancient collectors always sticking thier noses in.

Chris (2)