Alluaivite

Formula: Na₁₉(Ca,Mn)₆(Ti,Nb)₃Si₂₆O₇₄Cl^.2H₂O

Origin of name:  From occurrence at Mt. Alluaiv, Kola Peninsula, Russia

Crystal system:  Hexagonal

Crystal class:  3/m or -3 2/m

Twinning:

Unit cell: a = 14.046 Å, c = 60.60 Å

Colour:  Colourless, pink-brownish tint

Diaphaneity: Transparent.

Luster:  Vitreous

Habit:  Irregular accumulations to 1 mm, intergrown with eudialyte

Hardness:  5 to 6

Specific gravity:  2.76

Cleavage:  None

Tenacity:

Streak: White

Synonyms/varieties:

Comments:  Fluorescence vivid red-orange in UV. Found in ultra-agpaitic pegmatites in a differentiated alkalic massif