Melanterite is a perishable product of iron ore weathering, forming awesome green stalactites and crusts in the abandoned mines. Its shaky existence is a nice example of natural processes, but admiring melanterite beauty often includes trips to hardly accessible underground places.
Cinnabar is bright red mercury sulfide, which is a main ore of mercury and used to be a source of red pigments for milleniums. Cinnabar (and mercury) had been a key to mining precious metals until beginning of the 20th century and also saved a millions of teeth.
Elemental bismuth occurs as a metallic silver mineral often characterized by an oxide tarnish generating a dramatic iridescence of pinks, yellows and greens.
Elemental mercury occurs in the rare natural form as a silver liquid globules. Mercury has extreme physical properties combined with very high toxicity, which makes it a very unusual collectors specimen.
