Engelhard bar CUT IN HALF

[greendragon]

10 minutes ago, Pete said:

Do X-rays penetrate through silver ?
I don't know but I would assume they only test the surface.
What is the penetration depth ?

Obviously the bar is cast but the picture seems to show some impurities as the colour is not uniform.
Looks like cast iron which is brittle and I thought silver was quite ductile.

Found this article - http://about.ag/Engelhard-Fakes.htm
 

As I have absolutely zero experience in bars I am not intentionally casting doubt about this bar only keeping the thread alive with observations hoping to stimulate other views - all about gaining knowledge.

Penetration depth is calculated from the mass absorption coefficient and the "density". The density value ρ is expressed as a combination of the specific gravity of the material and the packing density.
First the path length L is calculated:
IL = I0 × exp -(μ/ρ)ρL
Next the penetration depth (τ) :
τ = 0.5 L×sin(θ)
This is the thickness of the sample contributing 99% of the diffracted intensity for a given incident angle θ.
If u use HSP, there's a  MAC calculator where u can calculate the penetration depth. All u need is the wavelength, chemical formulas, weight fraction of each, estimated packing density and angle of incident (w).

 

i think that answers your question

[Pete]

1 minute ago, greendragon said:

Penetration depth is calculated from the mass absorption coefficient and the "density". The density value ρ is expressed as a combination of the specific gravity of the material and the packing density.
First the path length L is calculated:
IL = I0 × exp -(μ/ρ)ρL
Next the penetration depth (τ) :
τ = 0.5 L×sin(θ)
This is the thickness of the sample contributing 99% of the diffracted intensity for a given incident angle θ.
If u use HSP, there's a  MAC calculator where u can calculate the penetration depth. All u need is the wavelength, chemical formulas, weight fraction of each, estimated packing density and angle of incident (w).

 

i think that answers your question

I like the last sentence  but with the type of x-ray sources / instruments available to the PM industry would the photons have sufficient energy to pass through this thickness of bar ?
I suspect not but maybe using an x-ray source from a nuclear burst equivalent might - something along the lines of VIPER at Aldermaston.

[fehk2001]

1 hour ago, greendragon said:

now I,M confused

i mean spot price for the half dog silver coin 

[greendragon]

1 minute ago, Pete said:

I like the last sentence  but with the type of x-ray sources / instruments available to the PM industry would the photons have sufficient energy to pass through this thickness of bar ?
I suspect not but maybe using an x-ray source from a nuclear burst equivalent might - something along the lines of VIPER at Aldermaston.

there was a thread on here somewhere explaining the use of x=ray,and i think it says how deep.

but i imagine anything capable of going straight through would need a white coat and some safety glasses at least

[greendragon]

1 minute ago, fehk2001 said:

i mean spot price for the half dog silver coin 

if its the lunar dog you are welcome to it! what a mutt!

[fehk2001]

Just now, greendragon said:

if its the lunar dog you are welcome to it! what a mutt!

no , not hotdog, 

lunar dog silver coin 

[kimchi]

11 minutes ago, greendragon said:

but i imagine anything capable of going straight through would need a white coat and some safety glasses at least

Whenever @fehk2001 pops up there are always plenty of white coats and safety goggles for everyone

[boon]

I might be wrong but it looks to me like the bar has been halved using a guillotine, or another method which places the material in shear. This literally tears the particles apart and gives the appearance as shown in the pics- that will be the grain of the metal. The area at the top could be as silver is soft, the top layers have been compressed and smoothed as the blade starts to compress the metal before shearing. Just my view, could be totally wrong- but it looks good to me.

Thinking about it, it makes sense to do it this way, as if you were to saw it, you'd lose the weight of the thickness of the cutting blade- and neither husband nor wife would have half, a little less. Unless they swept up and kept the filings of course!

[fourboysplus]

8 minutes ago, boon said:

I might be wrong but it looks to me like the bar has been halved using a guillotine, or another method which places the material in shear. This literally tears the particles apart and gives the appearance as shown in the pics- that will be the grain of the metal. The area at the top could be as silver is soft, the top layers have been compressed and smoothed as the blade starts to compress the metal before shearing. Just my view, could be totally wrong- but it looks good to me.

Thinking about it, it makes sense to do it this way, as if you were to saw it, you'd lose the weight of the thickness of the cutting blade- and neither husband nor wife would have half, a little less. Unless they swept up and kept the filings of course!

You are 100% correct. It has been sheared, that is why the top edge is shiny, it has been cut the bottom half has been essentially torn apart.

No Material has been lost as the weight is exactly 10oz.

[boon]

13 minutes ago, fourboysplus said:

You are 100% correct. It has been sheared, that is why the top edge is shiny, it has been cut the bottom half has been essentially torn apart.

No Material has been lost as the weight is exactly 10oz.

Apologies @fourboysplus i did miss your previous post stating that! Just re-read. Interesting, I hope it was done on a hydraulic one- either that or the fella who did it had a very very big leg.......!

Its a lovely piece, I love stuff like this. Bit of history to it and spot price- brilliant. Enjoy!