The berthierite has been named after Pierre Berthier the french geologist, who had noticed this mineral first in 1827, near Chazelles (Haute-Loire) in France. It is an interesting fact, that Berthier wanted to name it haidingerite, but then revealed that an other mineral existed on that name already. Thereafter the other affected person, Wilhelm Ritter von Haidinger the austrian mineralogist named berthierite after its explorer. Berthierite is a relatively rare iron antimony sulfide mineral, which can be confused with stibnite and miargyrite. In low temperature hydrothermal veins can be located together with stibnite and quartz, usually in fibrous, stringy, spiky stuffed aggregations. On its dark grey crystals we often see bronze, bluish or other colored luster. Nice specimens turned up in Transylvania (Romania) from Chiuzbaia and Baia Sprie. Localities: Romania, France, Germany, Czech Republic, USA, Bolivia etc.