Posted on 10/12/2022 4:17:56 PM PDT by BenLurkin
Zwischgold was used to gild sacred figures. It is not actually gold leaf, which was quite expensive, but a special double-sided foil of gold and silver where the gold can be ultra-thin because it is supported by the silver base.
Other microscopy techniques had been used previously to examine zwischgold, however, they only provided a 2D cross-section of the material. In other words, it was only possible to view the surface of the cut segment, rather than looking inside the material. The scientists were also worried that cutting through it may have changed the structure of the sample.
But an advanced microscopy imaging method used today, ptychographic tomography, provided a 3D image of zwischgold’s exact composition for the first time.
“Ptychography is a fairly sophisticated method, as there is no objective lens that forms an image directly on the detector,” Watts explained. Ptychography actually produces a diffraction pattern of the illuminated area, in other words, an image with points of differing intensity.
By manipulating the sample in a precisely defined manner, it is possible to generate hundreds of overlapping diffraction patterns. “We can then combine these diffraction patterns like a sort of giant Sudoku puzzle and work out what the original image looked like,” he said. A set of ptychographic images taken from different directions can be combined to create a 3D tomogram.
The advantage of this method is its extremely high resolution. “We knew the thickness of the zwischgold sample taken from Mary was of the order of hundreds of nanometers,” Watts said. “So we had to be able to reveal even tinier details.”
The 3D images show how thinly and evenly the gold layer is over the silver base layer.
(Excerpt) Read more at mining.com ...
Very interesting, but I disagree with the conclusions.
There is no way to hammer gold and silver into layers nanometers thick.
While I can think of ways to possibly do this, most involve electricity. Or aliens
They got four in an Igloo just south of
The Texas border and they Ain’t talking!
Rollers
30 nanometers is .03 microns
I am pretty sure you could not do that with rollers even today.
This topic was posted , thanks BenLurkin.
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