In 2017, a well known strahler from Aachen-Stolberg region posted a message on Mineralienatlas that he was cleaning up his garage and had 60kg of material from the area of Stolberg. The admin of Strahlen.org picked it up and repeated it on his site, and I was the lucky guy to collect the material at the house of the collector. It was much more than 60kg. The two main localities covered were Stolberg-Münsterbusch Birkengang and Zinkhütte Stolberg-Münsterbusch Heinrichshütte. And what a great material it was! The material is slag, which is a remnant from smelters (Zink Hütte). In these smelters, that originate from the late 18th and early 19th century, several complex steps were used to reveil silver, lead, zinc and copper out of rough ore. In some cases, these steps remind us of the ancient Alchemists. After being dumped, over time beautiful cristals grew on the slags. As with the material from Eijsden the slags shows lots of different and complex but small phases (minerals without official mineral status) but also pure metals (Silver, Copper,…).
The strahler that donated the material has written several articles in Mineralienwelt on the locality, allowing me to identify the minerals, and quite some pieces even carried his lables or tiny indicators. For a few of them a friend from Köln assisted with EDX and Raman. But many are not identified (correctly). Today one can barely find the slags at the former dump areas.
It was a huge but nice task to go through the material. The most difficult task was to put them all on pictures, archive them and then to select the best ones, and re-photograph them to get them just right..and this is still ongoing, hence the large amount of pictures of fluctuating quality. Most of the fields of view are less than half a cm down to just 2-3 mm. Especially the green and blue colors are just fantastic. Enjoy!