Mascagnite is a rare

ammonium sulfate Ammonium sulfate (American English and international scientific usage; ammonium sulphate in British English); (NH4)2SO4, is an inorganic salt with a number of commercial uses. The most common use is as a soil fertilizer. It contains 21% nitrogen a ...

mineral ( N H₄)₂ S O₄. It crystallizes in the

orthorhombic In crystallography, the orthorhombic crystal system is one of the 7 crystal systems. Orthorhombic lattices result from stretching a cubic lattice along two of its orthogonal pairs by two different factors, resulting in a rectangular prism with ...

system typically forming as stalactitic masses exhibiting good cleavage. It is soft (not higher than 2.5 on the

Mohs Scale The Mohs scale of mineral hardness () is a qualitative ordinal scale, from 1 to 10, characterizing scratch resistance of various minerals through the ability of harder material to scratch softer material. The scale was introduced in 1812 by ...

) and water-soluble. Optical properties are variable; the purest form is transparent and colorless, but opaque gray or yellow deposits are also known. It occurs in

fumaroles A fumarole (or fumerole) is a vent in the surface of the Earth or other rocky planet from which hot volcanic gases and vapors are emitted, without any accompanying liquids or solids. Fumaroles are characteristic of the late stages of volcan ...

, as at

Mount Vesuvius Mount Vesuvius ( ; it, Vesuvio ; nap, 'O Vesuvio , also or ; la, Vesuvius , also , or ) is a somma-stratovolcano located on the Gulf of Naples in Campania, Italy, about east of Naples and a short distance from the shore. It is one of ...

and associated with

coal seam fire A coal-seam fire is a burning of an outcrop or underground coal seam. Most coal-seam fires exhibit smouldering combustion, particularly underground coal-seam fires, because of limited atmospheric oxygen availability. Coal-seam fire instances ...

s. It was named for Italian anatomist

Paolo Mascagni Paolo Mascagni (25 January 1755 – 19 October 1815) was an Italian physician and anatomist. He is most well known for publishing the first complete description of the lymphatic system. Biography Early life Mascagni was born in the co ...

(1752–1815) who first described the mineral.

References

Ammonium minerals Sulfate minerals Orthorhombic minerals Minerals in space group 62 Mount Vesuvius {{sulfate-mineral-stub