Chalk Chrystal 6 Pieces Raw Minerals Stones Rocks Collecting

Lot 6 Gypsum Crystals of Albano Volcano 13.9 gr total weight-  mm 33-47 Minerals Stones Rocks for Collection, as in photo.
Farneto (Italy Emilia) Gypsum Crystals are also available at this link.

On the edge of the Tor Caldara Nature Reserve (Italy, Lazio, Anzio), a cliff of about ten meters overlooks the sea, carved into clay and sandy soils.
Near the sea, the area is characterized by the emergence of a sulfur mineralization which, in the past, has given rise to very important mining interests.
Precisely at sea level mineralization seems to be more pronounced in the presence of strong gaseous emanations, and it is here that our gypsum crystals have been found outside the reserve, close to the beach.
These, which sometimes reach 6-8 cm in length, are well formed, limpid and often with the characteristic "lance iron" gemination.
Crystals tend to emerge in some distinct sectors of the sulfatara, while in others they seem to be completely absent; spherules of a few centimeters with a fibrous-radiated structure were also found.
The formation environment of sulfur and other minerals is to be included in the typical manifestations of an exhalation-fumarolic-hydrothermal environment, linked to post-volcanic events.
In fact, the Tor Caldara mineralization can be directly related to the other sulphurous manifestations located south of Rome, arranged according to an approximate north-south alignment and falling within the south-western sector of the Lazio Volcano, from which they are a few tens of kilometers away.
In the sulfatara, besides the gypsum crystals, sulfur and marcasite are also found in crystals also well formed. There are also alunite, jarosite, melanterite, halotrichite, generally in the form of millimeter-sized tufts, for which identification is generally necessary to resort to X-ray diffraction analysis. The Goethite and limonite panorama is completed in patinas and incrustations sometimes very showy. Moreover, the diffractometric examination has almost constantly highlighted the presence of quartz, calcite, feldspar, biotite and more rarely pyroxene, minerals that are part of the composition of fluvial-lacustrine sand of the Plio-Pleistocene age.