Images
Formula: Mn2+5Si8O20(OH)2.7H2O
Phyllosilicate (sheet silicate), palygorskite group,
manganese-bearing mineral
Crystal System: Nonoclinic
Specific gravity: 2.18 measured, 2.82 calculated
Hardness: 2½
Streak: Light pink
Colour: Pink to pale violet, brown
Common impurities: Ti,Al,Cr,Zn,Ca,K
Environments
Pegmatites
Hydrothermal environments
Localities
At the type locality, the Poudrette quarry, Mont Saint-Hilaire, La Vallée-du-Richelieu RCM, Montérégie, Quebec, Canada,
yofortierite is a late-stage hydrothermal mineral that occurs as pink to violet radiating fibres up to 3 cm long
in pegmatite veins in
nepheline syenite. Associated minerals include
analcime, serandite,
eudialyte, polylithionite,
aegirine, altered microcline and
albite
(CM 13.68-74).
At the Karnasurt Mountain, Lovozersky District, Murmansk Oblast, Russia, yofortierite is associated with
kuzmenkoite-(Zn). Other minerals associated with
kuzmenkoite-(Zn) here include
natrolite, microcline,
albite, aegirine,
nepheline, arfvedsonite,
sodalite, eudialyte,
organovaite, beryllite,
ranciéite, elpidite,
catapleiite,
manganoneptunite and
nontronite
(Minrec 35.4.356).
Back to Minerals