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Formula: NaCa2Si4O10F
Inosilicate (chain silicate)
Crystal System: Triclinic
Specific gravity: 2.902 measured, 2.887 calculated
Hardness: 5½
Streak: White
Colour: White to greyish or greenish white
Luminexcence: Fluoresces bright pink under long wave UV and duller pink under short wave UV
Environments
Plutonic igneous environments
Pegmatites
Common associates of agrellite include aegirine,
eudialyte, miserite and
quartz
(Mindat).
Localities
At the type locality, the Kipawa alkaline complex, Les Lacs-du-Témiscamingue, Témiscamingue RCM,
Abitibi-Témiscamingue, Quebec, Canada, agrellite occurs in the
regionally metamorphosed
agpaitic rock complex. It is found in
pegmatitic lenses and pods and in
mafic gneisses composed
principally of albite,
microcline,
alkalic amphibole
(katophorite-arfvedsonite),
aegirine-augite with or without
eudialyte and nepheline; in
addition, the following minerals are found in small but widely varying amounts:
hiortdahlite, other members of the
wöhlerite group,
mosandrite-(Ce),
miserite, britholite,
vlasovite, calcite,
fluorite, gittinsite,
clinohumite, norbergite,
zircon, biotite,
phlogopite and galena. The
commonest
occurrence is in the pegmatitic pods which have probably
resulted from partial melting of the agpaitic rocks during
amphibolite facies metamorphism. Agrellite
forms white to greyish or greenish white crystals from a few mm up to 100 mm in length
(Canadian Mineralogist: 14: 120-126, HOM).
At the Stettin pluton, Wausau Intrusive Complex, Marathon county, Wisconsin, USA, agrellite is associated with
miserite, aegirine,
eudialyte and quartz
(HOM).
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