Branched 4er single ring of Eakerite Data from: Kossiakoff A. A., Leavens P. B. (1976): The crystal structure of eakerite, a calcium-tin silicate, American Mineralogist 61 pp. 956-962 http://rruff.geo.arizona.edu/AMS/download.php?id=00540.cif&down=cif Calculation of image data: Larry W. Finger, Martin Kroeker, and Brian H. Toby, DRAWxtl, an open-source computer program to produce crystal-structure drawings, J. Applied Crystallography V40, pp. 188-192, 2007 http://www.lwfinger.net/drawxtl/ Rendering: POVRAY — Photo: Bubenik · CC BY-SA 3.0
Eakerite
Eakerite is an IMA-recognized mineral species in the silicate class, with the chemical formula Ca₂Sn⁴⁺Al₂Si₆O₁₈(OH)₂·2H₂O.
It crystallizes in the monoclinic crystal system (space group P2_1/a).
Key properties: Mohs hardness 5.5; specific gravity 2.93; Vitreous luster; optically biaxial.
IMA symbol Ea, IMA status: approved, named in 1969.
Probably of hydrothermal origin, in a seam in spodumene-bearing pegmatite (Foote mine, North Carolina, USA); as exsolved inclusions in stanniferous andradite (Kitel'skoye deposit, Karelia).
It is found associated with Tetrawickmanite, bavenite, quartz, albite (Foote mine, North Carolina, USA); andradite (Kitel'skoye deposit, Karelia).
In honor of Jack Eaker, mineral collector of Kings Mountain, North Carolina, USA, who discovered the mineral.