Lévyne-Ca
Lévyne or lévynite is a group of zeolite minerals, i.e. hydrated silicate minerals. There are two members of the group: Lévyne-Na, the sodium-dominant species (Na2,Ca,K2)Al2Si4O12·6H2O, and Lévyne-Ca the calcium-dominant species (Ca,Na2,K2)Al2Si4O12·6H2O Lévyne crystallizes in the trigonal crystal system and belongs to the hexagonal scalenohedral crystal class. It typically occurs as radiating clusters or fibrous masses that are transparent to translucent in colors ranging from white through reddish and yellowish white to gray.
Intro adapted from Wikipedia (CC BY-SA).
Lévyne-Ca is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₃(Si₁₂Al₆)O₃₆·18H₂O.
It crystallizes in the hexagonal crystal system (space group R-3m). It is a member of the Lévyne structural group.
Key properties: Mohs hardness 4–4.5; specific gravity 2.09–2.16; White streak; Vitreous luster; optically uniaxial.
IMA symbol Lév-Ca, IMA status: approved, named in 1825.
Typically as a crystalline lining in cavities in basalts.
It is found associated with Zeolites, especially offretite and erionite.
The name commemorates Armand L¶ evy (1794–1841), French mineralogist and crystallographer.