Semenovite-(Ce)

Semenovite-(Ce) is a very rare, Be and Ce bearing silicate mineral from the type locality in Greenland (Taseq, Ilímaussaq Complex, Kujalleq, Greenland). It forms sharp orange-brown crystals in matrix in association with colourless epididymite. Very sought after species from Greenland. — Photo: David Hospital · CC BY-SA 4.0

Semenovite-(Ce)

Semenovite-(Ce) is an IMA-recognized mineral species in the silicate class, with the chemical formula (Na,Ca)₉Fe²⁺Ce₂(Si,Be)₂₀(O,OH,F)₄₈.

It crystallizes in the orthorhombic crystal system (space group P4_2/n).

Key properties: Mohs hardness 3.5–4; specific gravity 3.14; Vitreous, to dull when altered luster; optically uniaxial.

IMA symbol Smv-Ce, IMA status: approved, named in 1971.

A late-stage hydrothermal mineral developed in cavities within albitite veins cutting alkalic igneous rocks.

It is found associated with Epididymite, eudidymite, \lithium-mica, " albite.

The mineral was named to honor Professor E.I. Semenov, Russian mineralogist, Institute of Mineralogy and Geochemistry of Rare Elements, Moscow, Russia.