Technical Details

General

The original relief measures 25.9 x 16.4 centimeters and weighs 195 grams.

Result of the atomic absorption analysis (AAS)

In 2004, a material sample was taken from the back of my original relief and an atomic Absorption Analysis was performed on this sample with the following results:

Copper (Cu) 99.97%
Tin (Sn) <0.25%
Lead (Pb) <0.04%
Zinc (Zn) 0.003%
Iron (Fe) 0.02%
Nickel (Ni) <0.01%
Silver (Ag) 0.006%
Antimony (Sb) <0.05%
Arsenic (As) <0.10%
Bismuth (Bi) <0.025%
Cobalt (Co) <0.01%
Gold (Au) <0.02%
Cadmium (Cd) <0.002

If one compares the results of other studies, one recognizes that there the detection limit for the following elements was substantially lower, and that already in the 80's of the last century.
For example for:

Tin (Sn) to 0.1
Lead (Pb) to 0.02
Antimony (Sb) to 0.01
Arsenic (As) to 0.01
Bismuth (Bi) to 0.002
Gold (Au) to 0.0003

The analysis carried out of my original relief did not seem to measure so accurately, otherwise more elements would have been detectable.

My original relief would probably be made of solid copper, since it is all copper, with exeption of a few minor additions.

Examination with the scanning electron microscope

Overview of the ground sample of the original relief

From original relief, a sample was taken and made a "cut sample" of it. This grind sample was etched with ammonium peroxide sulfate solution to visualize the micrograph. Below the overview and two pictures of the structure.

Bereich 1 of the sample of the original relief

The "Bereich 1" also includes the surface, which was probably galvanized in the 19th century. Originally the relief was gilded on the front and you can still see traces of it in more hidden places.

Bereich 2 of the sample of the original relief

So in "Bereich 2" you can see the stem-shaped, fine microstructure of the warm-driven relief made by solid copper.

The deformation is quite typical in the direction of the heat flow. Since the metal is less than one millimeter thick, the heat flow direction is both up and down.

On the other hand, the microstructure of the recently acquired galvanoplast shows a very different picture. Also, a sample was taken and made a grinding sample. Here, too, etching was carried out with an ammonium peroxide sulfate solution in order to visualize the microstructure.

Gefügebild der Schliffprobe des Galvanoplastes

Here you can see the typical for this technique, largely from top to bottom passing stems. The structure is rough. The underside of the illustrated cut is the back of the galvanoplast. The underside of the cut is heavily dented and corresponds to the coarse-grained surface of the galvanoplasts.
(See Point "Comparison with Galvanoplast").

My research on the microstructure of metals has shown that in cubic solidifying metals, including copper, the crystallization form largely depends on the cooling conditions and the composition.
Stem crystals form with uneven or directed heat dissipation, whereby the crystals deform in the direction of heat dissipation. Dentrites are formed only with a higher content of impurity or alloying elements. (see: Werkstoffkunde, edited by Hans-Jürgen Bargel and Günter Schulze, 7th edition, 2000, pages 10 and 20f)

Similarly, the description of a cast structure with 3 zones are described in the cooling:
The concrete formation of the cast structure, the relations of the zones to one another, the grain size, etc., depend on the alloy composition or the purity of the metal, the thermal properties of the casting mold, the melt starting temperature and the cooling resistance (see: Metallografie, edited by Hermann Schumann and Heinrich Oettel, 14th edition, 2005, pages 463ff).

From the above referencet follows that the deformation of the structure in the direction parallel to the direction of heat flow occurs and that the

Speed of cooling,
the alloy or purity of the metal as well
the property of the mold has an effect on the microstructure.

The stalk-shaped formation in the microstructure of my original relief is therefore typical of a multiheated and cooled again metal.

It is therefore incorrect that a stalk-shaped microstructure proves a galvanic production.

Traces of driving

With the photomicroscope I have discovered on my original relief traces that suggest the production by driving. On the front you can see stitches, on the back you can see the corresponding bulges. This is also a strong proof that my relief is not a galvanoplast but a work made of chased copper. The stitches are likely to be final editing traces, after which my relief was then not heated much. These tracks are clearly visible on the front as well as the back.

Bendable or rigid?

An expert on silver objects also gave me a very important hint for the demarcation between a driven metal object and a galvanic manufactured object.
A Galvanoplast is therefore rigid and can not bend, a driven metal work, however, can bend well. Since I am also in possession of a Galvanoplastes, I can directly compare the original relief and the ganvanic made relief (Galvanoplast). The original relief can be bent very well, but the galvanoplast I acquired for comparison is totally rigid. Further proof that the original relief is a driven manual work.

Conclusio

All in all, these are very strong indications that the original relief is certainly not a galvanoplast but a work made of chased copper.

the material used is pure copper due to its purity
the microstructure is typical of a multi-heated and re-cooled thin metal work
there are traces of drifting on the back
my original-relief is not rigid but well bendable