Message:

<p>[QUOTE=&quot;The Eidolon, post: 4205590, member: 102103&quot;]This seems like a very reasonable explanation, thanks.&nbsp; The lines are very nearly parallel so are unlikely to be formed post-striking.&nbsp; Differential rates of oxidation nucleating on scratch sites could account for the color difference even if the oxide thickness difference is slight.&nbsp; As for how the scratches can survive striking, even if the pressure of the strike is high enough to cause plastic deformation of the planchet, it is a fast and low-temperature process which perhaps is not enough to cause much smoothing of the surface at the micro level.&nbsp; It would be an interesting experiment to look at a planchet before and after striking with something like an atomic force microscope to see how much of the surface texture survived.&nbsp; I would bet a lot.&nbsp; Even if the high points are flattened a bit, any grooves or scratches are probably too recessed to be much affected.[/QUOTE]</p><p><br /></p>

Your name or email address:

Do you already have an account?

• No, create an account now.
• Yes, my password is:
• Forgot your password?

Stay logged in