Charoite , Aegirine , Fedorite Dimension: 4,3 cm x 3,3 cm Locality: Vostochnyi Mine, Murun-Massif, Yakutia, Russia Description: Fibrous foliated Charoite aggregation with black radiating Aegirin („Aegirin suns“) and orange Fedorite crystals. — Photo: Ra'ike (Wikipedia) · CC BY-SA 3.0 de
Fedorite
Fedorite is an IMA-recognized mineral species in the silicate class, with the chemical formula (K,Na)₂.₅(Ca,Na)₇Si₁₆O₃₈(OH,F)₂·3.5H₂O.
It crystallizes in the triclinic crystal system (space group P-1). It is a member of the Gyrolite structural group.
Key properties: specific gravity 2.43–2.58; Vitreous, satiny, pearly luster; optically biaxial.
IMA symbol Fdr, IMA status: approved, named in 1965.
Found in fine veinlets in fenitized sandstone (Turii Peninsula, Russia).
It is found associated with Narsarsukite, quartz, apophyllite (Turii Peninsula, Russia).
The name refers to Evgraf Stepanovich Fedorov (1853–1919), eminent Russian crystallographer, Mining Institute, St. Petersburg, Russia.