Selenite 1 Piece Raw Minerals Stones Rocks Collecting (1)

Selenite 1 Piece 11-25 gr - cm 2.5-4.5 Raw Minerals Stones Rocks for Collection Gypsum Crystals.

The Selenite is a particular variety of crystalline Gypsum (secondary Gypsum), chemically calcium sulfate dihydrate (CaSO4 · 2H2O), which has the particularity to be deposited in layers. It is found in nature in the form of flakes, transparent translucent that are crossed by the light.
This feature gives rise to its name, in fact thanks to the use that the Greeks made it for the manufacture of transparent plates which had glass function, still unknown, the light that betrayed was similar to that of the moon (σεληνη selene in greek) . For this reason it is also known by the name moonstone.
Even in Roman times it was used as a building material for windows as lapis specularis when the flat glass manufacturing was still unknown.
Finely ground and calcined between 130 ° and 170 ° gives rise to the scagliola.
In Italy selenite is widespread in the Emilia-Romagna region. In 2011 within the Chalk Vein Regional Park it has been identified in the cave of Lucerna, the first of a series of Roman mines of lapis specularis. In Bologna, the surrounding landscape is dominated by the chalk hills / selenite whose many quarries have supplied the precious mineral city, which he has served since the Roman period. There is another extraction area of ​​selenite in Sicily. The highest concentration of lapis specularis quarries in the Roman era has been identified in Spain near the town of Segobriga, but also Tunisia, Cyprus and the region of Cappadocia, in present day Turkey, were exploited for the extraction of valuable product . Plinio visited the Spanish quarries and wrote extensively in his work.