Čechite, a rare vanadate from the Ulldemolins mines (Catalonia)

Čechite is a very rare lead and iron hydroxylvanadate, with the formula PbFe²⁺(VO₄)(OH), which has been found in very few localities worldwide. The first world location in which it was determined was in the Vrančice mines, in the Czech Republic, in the early 1980s. It has subsequently been found in Italy and the United States. It has no industrial interest, despite the fact that vanadium is a strategic element, since this mineral occurs in small quantities. 

This species usually appears as small tabular to equidimensional crystals, with a black color and a resinous to submetallic luster. The best crystals known until recently were those of the Czech Republic.