Villiaumite
NaF

     Very rare before 1982 at MSH, villiaumite has been found more frequently in sodalite xenoliths in nepheline syenite. It displays a
weak red fluorescence under SW.

PHYSICAL CHARACTERISTICS:

Color ranges from pale orange-red to very deep carmine red.
Luster is vitreous on clevages, and vitreous to waxy on faces.
Diaphaneity is transparent with inclusions.
Crystal System is isometric; Fm3m.
Crystal Habits include fillings or partial fillings up to 10cm in size,
   very rarely as sharp cubic or octahedral crystals up to 10mm.
Cleavage {001} is perfect.
Fracture is conchoidal.
Hardness is 2- 2.5
Specific Gravity is approximately 2.8 g/cm³.
Streak is white.
Associated Minerals include amphibole group, calcite, eudialyte,
   fluorite, nepheline, pectolite and numerous other minerals from
   sodalite xenolith environments.
Distinguishing Features: Crystal habit and color.
Origin: Named in 1908 for Mr. Villiaume, French explorer, in whose
   collection of rocks from Guinea the mineral was first found.

CLASSIFICATION:

REFERENCES:
MinRec 21:345 (1990), Dana 8:375-376 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

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