How to prepare mined black silver from water for further processing

As many of you know, even silver of high purity suffers greatly from prolonged exposure to water. A thick black patina begins to form on the surface, which grows into a crust with prolonged exposure to water, and this crust begins to stick to the surrounding grains of sand, etc.

Of course, you cannot work with such material and if you want to make something else out of it, or keep it as an investment in precious metals, you have to rework the material. You can use chemistry and try to clean the jewellery, but it is still a lot of work afterwards and you can't avoid melting it anyway.

In this case, we'll be preparing the material for the assay office, where they'll re-melt the material and make the alloy homogeneous purity into an ingot, for which they will issue all the necessary documents and state marks. This document is then an official finding and is an indisputable proof of the ingot's purity, weight and is a generally accepted document.

Logically, however, you can't bring silver there in a found condition encased in a crust of sand, the second reason being discretion. In fact, I think so many people go there that they've certainly encountered "black silver" out of the water, but I still didn't really want to get unnecessary questions like "how and where did you get it" and the like....

Another advantage is that if you process the material this way, there is already minimal weight loss through smelting, not to mention that they probably wouldn't take such black silver from you in the first place.

The first thing to do is to carefully re-inspect all the material and make sure that in all cases it is precious metal. Next, you need to get rid of any stones in the jewellery, and be especially careful of chain carabiners and earrings that contain metal springs - these must of course be removed.

If you want to make something out of the resulting material in the future, it is necessary to sort out only pieces of the same purity, and even in this case I would recommend throwing in a small piece of pure silver, because the silver solder used has a lower purity (around 600/1000), so that you can be sure that you will not fall below the required purity.

Occasionally there is gold :D

I have found the most efficient and fastest way is to melt the silver and then cast it in water, which produces a granulate that often resembles corn flakes.

The advantage of this granulate is that it can be easily rechecked (the flakes are really thin). It is a good idea to double check that there are no foreign particles in the material. In our case we melted a total of 23g of black heavily oxidized silver in the first batch, the resulting granulate had a weight of 22.3g (it isafter the granulate was melted into a bar it was 21.96g - so the weight loss in this case was about 1g per 23g of input material.

Occasionally, after casting in water, pieces resembling Celtic irises are formed

For further processing, I still put the resulting granulate in battery acid for a few hours, as it then turns beautifully white. Then I repeat the whole melting process again and throw in a small piece of pure silver. Theoretically you can already use the granulate for hallmarking, in my case I melted it once more and cast it into the shape of a bar.

With this reworked material you can already make a punch, but that will be the next part of this article.