EUDIALYTE
Eudialite in lakarpite from Norra Kärr (The Northern March), county Småland, Sweden
Eudialyte crystals are tabular, rhombohedral, or prismatic. Eudialyte is yellowish brown, to brownish red, red, or pink in colour, and the streak is colourless. It is a translucent mineral, and has a vitreous to dull lustre.
It forms in coarse-grained acid and intermediate igneous rocks and is easily dissolved in acids.
Lakarpite is a nepheline (feldspar) rock containing, nepheline, eckermannite and arfvedsonite. Also in this sample are some very rare (beige) crystals of rosenbuschite.
Group: Silicates
Composition: Na4(Ca,Ce)2(Fe+2Mn+2Y)ZrSi8O22(OH,CI)2
Hardness: 5-5.5
SG: 2.74-2.98
Cleavage: Indistinct
Fracture: Uneven.
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