Realgar 1 Piece Raw Minerals Crystal Stones Rocks Collecting (3)

Realgar 1 Pezzo 8 gr - cm 2.7 x 2 x 1.7 Raw Minerals Crystals Stones Rocks for Collection, only a piece, as in photo.

Realgar is a mineral, arsenic sulfide. The name comes from the Arabic rahj al ghar, "cave dust". Pliny the Elder in his Naturalis Historia mentions the mineral as "sandaraca" or "sandracca". In the Middle Ages, by alchemists, who called the mineral "risigallo", it was used as a medicine.
Crystalline habit presents itself in squat prismatic crystals of bright red color often streaked with green color, compact aggregates with fine grain. Usually it can also be found in earthy, coarse powdery masses or as incrustation.
It has hydrothermal genesis, cold springs, particularly associated with other iron sulphides and arsenic sulphides, but also as a product of volcanic sublimation, in fumaroles and in the deposits of hot springs and in sedimentary rocks (dolomites and bituminous schists). It can also be found in metal deposits sometimes associated with orpiment, antimonite and other sulphides.
Mines and find sites are found in Romania, Macedonia, Switzerland, Saxony, Bohemia, Corsica, France, Georgia, Iran, Turkey, Utah, Nevada, California, and Peru.
In Italy it is found in the Solfatara di Pozzuoli, in Valtellina, in Val Malenco, in some cinnabar mines of Monte Amiata, and in bituminous limestones of Friuli-Venezia Giulia.
It is composed of 29.9% sulfur and 70.1% arsenic. The samples must be kept away from light because the crystals disintegrate easily if exposed, due to the content of arsenolite, orpiment, pararealgar and other photosensitive arsenic sulphides, decomposing into a reddish-yellow powder.
This mineral is used to extract arsenic or to obtain compounds of the same element. In the past, mixed with saltpeter it was used to make fireworks and a painting pigment.