Purple-red eudialyte on dark green arfvedsonite. Field of view is 0.8 cm left to right. From Kola Peninsula, Russia. (Photo by W. Cordua.)

Formula: Na15Ca6(Fe,Mn)3Zr3Si25O73(O,OH,H2O)3(OH,Cl)2 Hexagonal


Eudialyte is a rare mineral found in pegmatitic low-silica igneous rocks.

MARATHON COUNTY: Pale yellow anhedral grains of eudialyte with locally pinkish cores were found in a gneissic syenite in the NE NE Sec. 27 T.29N R.6E, near Stettin. Associated minerals were nepheline, zircon, microperthite and fluorite (Geisse, 1951; Stobbe and Murray, 1956).