Villiaumite

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Villiaumite crystals - click for larger pic
Beautiful villiaumite crystals
László Horváth specimen
Photo by Violet Anderson
© Royal Ontario Museum

Villiaumite crystals - click for larger pic
Villiaumite crystal
© Gilles Haineault

Villiaumite crystals - click for larger pic
Villiaumite crystals
© Doug Merson

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; Fm
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/cm
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:

Dana System
# 9.1.1.3

Strunz Classification
# III/A.02-10

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

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

MSH
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