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Franconite aggregates
L. Horváth sp.
Photo by Violet Anderson
© Royal Ontario Museum
Franconite crystals
© Doug Merson
Franconite crystals
© Modris Baum
Franconite crystals
© Stephan Wolfsried
NaNb11 · 9H
At MSH, the second known locality for this mineral, it had been recognized as a new species and designated for a number of years as UK #43.
It bears very close ressemblance to hochelagaite, its Ca-analog and a few other minerals. In the paragenetic sequence in all modes of occurrence, franconite appears to be one of the latest minerals formed.
PHYSICAL CHARACTERISTICS:
Color is white to colorless.
Luster is vitreous to silky.
Diaphaneity: the crystals are transparent to translucent.
Crystal System is monoclinic; (??).
Crystal Habits normally as radiating short white capillary crystals
from a solid core to 1-2mm.
Cleavage none.
Fracture is (??).
Hardness is (??).
Specific Gravity is approximately 2.7 g/cm
Streak is white.
Associated Minerals include aegirine, albite, analcime, calcite,
catapleiite, dawsonite, gaidonnayite, microcline, natrolite, pyrite,
siderite and sodalite.
Distinguishing Features include its fluorescence, which helps
in distinguishing it from hochelagaite.
Origin: Named in 1984 for its discovery locality in the Francon quarry,
St-Michel, Québec, Canada.
CLASSIFICATION:
Dana System
# 8.6.1.1
Strunz Classification
# IV/D.06-40
REFERENCES:
CanMin 22:239-243 (1984), MinRec 21:310 (1990), Dana 8:367 (1997)
DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:
MSH
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Franconite crystals
© Elmar Lackner
Franconite crystals
© Elmar Lackner
Franconite crystals
© Steven Stuart