Eudialyte
Image: Robert M. Lavinsky (CC BY-SA 3.0)
Mineral NameEudialyte
Chemical Formula(Na,Ca)₅(Fe,Mn)ZrSi₆O₁₈(OH,Cl)₂
Mohs Hardness5
Crystal Systemtrigonal
Lustervitreous
Streak Colorwhite
Cleavagepoor/indistinct on {0001}
Fractureconchoidal
Specific Gravity2.7
Colorsred, reddish-brown, pink
Transparencytranslucent
Type LocalityKangerdluarssuq Firth, Ilimaussaq complex, Narsaq, Greenland
Mineral GroupSilicates
Usescollector, minor gemstone, potential source of zirconium
Associated Mineralsaegirine, nepheline, arfvedsonite
Rarityuncommon
Description
This specimen showcases reddish-brown to deep red, somewhat blocky crystals of eudialyte, often exhibiting a vitreous luster, embedded within a matrix that also contains dark, needle-like aegirine crystals.
Geological Context
Eudialyte is a rare cyclosilicate mineral typically found in nepheline syenites and other alkaline igneous rocks, forming during late-stage magmatic crystallization in peralkaline intrusions like the Ilimaussaq complex.
