Davyne - Encyclopedia
Class : Silicates
Subclass : Tectosilicates
Crystal system : Cubic
Chemistry : (Na,Ca,K)8Al6Si6O24(Cl,SO4,CO3)2-3
Rarity : Very rare
Davyne is an extremely rare mineral from leucite lavas, very deficient in silica, which is also found in the ejecta of Italian volcanoes. Davyne belongs to the cancrinite group, of which it designates the chlorinated terms, the carbonated terms constituting cancrinite in the strict sense. It was named in honor of the English chemist Sir Humphrey Davy who described certain chemical elements. Davyne occurs as colorless to white, vertically streaked, hexagonal prismatic crystals associated with nepheline and leucite, as well as vesuvianite and scapolite in volcanic ejecta.
Main photo : Davyne from Mount Somma, Naples, Italy © Matteo Chinellato
Davyne in the World
Twinning
No twin known for this mineral species.
Fakes and treatments
No fakes listed for this mineral species.
Hardness : 5.5 to 6
Density : 2.42 to 2.53
Fracture : Irregular to conchoidal
Streak : White
TP : Translucent to transparent
RI : 1.515 to 1.522
Birefringence : 0,004
Optical character : Uniaxial +
Pleochroism : None
Fluorescence : None
Solubility : Acids
Magnetism : None
Radioactivity : None