Ussingite

Ussingite is a silicate mineral with formula Na₂AlSi₃O₈(OH).^[3]

Ussingite
Ussingite from Shkatulka pegmatite, Umbozero mine (Umbozerskii mine), Alluaiv Mt, Lovozero Massif, Kola Peninsula, Murmanskaja Oblast', Northern Region, Russia
General
Category	Phyllosilicate minerals
Formula (repeating unit)	Na2AlSi3O8OH
Strunz classification	9.EH.20
Crystal system	Triclinic
Crystal class	Pinacoidal (1) (same H-M symbol)
Space group	P1
Identification
Color	pale to medium violet, reddish violet; sometimes barely tinted purple
Fracture	irregular/ uneven
Tenacity	brittle
Mohs scale hardness	6-7
Luster	sub-vitreous
Streak	white
Diaphaneity	transparent, translucent
References	[1][2]

It was named for Niels Viggo Ussing (1864–1911), Copenhagen, Denmark.

This article uses material from the Wikipedia article  Metasyntactic variable, which is released under the  Creative Commons Attribution-ShareAlike 3.0 Unported License