Franconite
Na₂Nb₄O₁₁ · 9H₂O

     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/cm³
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:

REFERENCES:
CanMin 22:239-243 (1984), MinRec 21:310 (1990), Dana 8:367 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

Legend