Fenaksite

fenaksite

nepheline

delhayelite

eudialyte

Images

Formula: KNaFe²⁺Si₄O₁₀
Inosilicate (chain silicate), litidionite group
Crystal System: Triclinic
Specific gravity: 2.744 measured, 2.74 calculated
Hardness: 5 to 5½
Colour: Light rose
Solubility: Decomposed by acids with the deposition of silica
Common impurities: Ti,Al,Mg
Environments

Pegmatites

Localities

The type Locality is the Material'naya Adit, Yukspor Mt, Khibiny Massif, Murmansk Oblast, Russia.

On Mts. Rasvumchorr and Yukspor, Khibiny massif, Kola Peninsula, Russia, fenaksite occurs in pegmatites associated with an ijolite-urtite intrusion in a differentiated alkalic massif. Associated minerals include albite, nepheline, aegirine-augite, delhayelite and eudialyte (HOM).
Fenaksite from the Ravumchorr Mountain - Image

Back to Minerals