FORVM`s Classical Numismatics Discussion Board

Numism => Reading For the Advanced Ancient Coin Collector => Topic started by: Frans Diederik on June 01, 2006, 05:06:06 pm

Title: clashed dies? Claudius Gothicus
Post by: Frans Diederik on June 01, 2006, 05:06:06 pm
While making an inventory of my coins 'in time to be sold'  I came across this one, with a clear negative impression of a head on the reverse. I remember the thread about clashed dies we had about a year ago, but I am still baffled about how this negative impression UNDER a positive image of (in this case) Victoria, came about.
Anyone who can explain this phenomenon to (perhaps not too bright) me, is invited.


Frans
Title: Re: clashed dies? Claudius Gothicus
Post by: mauseus on June 01, 2006, 05:21:15 pm
Hi,

A restruck brockage perhaps......? Or clashed dies where the impression made is going to be shallower than the central cut image so would only be imparted on the fields, yes? Well, you know what I mean, the red is the positive impresion on the die left by the negative of the clashing die so would appear underneath the struck coin.

Regards,

Mauseus
Title: Re: clashed dies? Claudius Gothicus
Post by: Heliodromus on July 14, 2006, 10:20:20 pm
Franz,

Here's what seems to happen with a die clash. The obv die has the large central bust, and the rev die has some more varied design. You can see that the result of striking a coin after the die clash is that the reverse die will impart on the flan not only the raised reverse design, but also a sunken (incuse) obverse design. It's not all all intuitive until you see the diagram (I just came up with this the other day trying to figure it out for myself).

You can see from this drawing that with a die clash the portion of the raised design over the incuse area may actually appear enhanced (i.e. unaffected) relative to the rest of the coin, whereas for a restruck brockage I think the opposite would occur - the incuse area of the flan would be less likely to fully meet the die on the second strike, and the raised design in that area is likely to be weak.

It also seems that it's the bust that will show up most clearly on a die clash since it's a large mostly/wholly incuse area on the die, surrounded by the higher mostly uncut legend area which will therefore hit the other die first leaving an imprint of the bust. With a more varied design such as a typical reverse design, there's not typically going to be such a large differerence in the distribution of contact areas when the dies meet, and therefore less of an imprint/effect (the force is more evenly distributed).

Ben