"Zinkenite is a steel-gray metallic sulfosalt mineral composed of lead antimony sulfide Pb9Sb22S42. Zinkenite occurs as acicular needle-like crystals.
It was first described in 1826 for an ...
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occurrence in the Harz Mountains, Saxony-Anhalt, Germany and named after its discoverer, German mineralogist and mining geologist, Johann Karl Ludwig Zinken (1790–1862)." - (en.wikipedia.org 26.11.2019)