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Sodalite crystals - click for larger pic
Sodalite crystal
Photo by Violet Anderson
© Royal Ontario Museum

Sodalite crystals - click for larger pic
Sodalite crystal
Photo by Violet Anderson
© Royal Ontario Museum

Sodalite crystals - click for larger pic
Sodalite crystals
© Modris Baum

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Home > Mineral Descriptions > Sodalite - (6 Photos)



Sodalite
Na8Al6Si6O24 Cl2

     Sodalite is a very widespread species at MSH, being one of the prime constituents of sodalite syenite. It fluoresces intense orange to orange-red under SW and LW and displays strong yellowish white phosphorescence for a short period. The hackmanite variety will fade with time, it will regain a darker shade when exposed to sunlight or ultraviolet radiation.

PHYSICAL CHARACTERISTICS:

Color is usually colorless to pink, pale violet, pale to dark blue, violet.
Luster is vitreous to greasy or dull.
Diaphaneity is transparent to opaque (dependant on size).
Crystal System is isometric; P43nc.
Crystal Habits include dodecahedra, rarely octahedra or distorted and
   elongated dodecahedra.
Cleavage {001} is poor.
Fracture is uneven to conchoidal.
Hardness is 5.5 - 6.
Specific Gravity is approximately 2.2 g/cm3.
Streak is white.
Associated Minerals include amphibole group, analcime, ancylite-(Ce) ,
   calcite, cancrinite, dawsonite, eudialyte, fluorite, gonnardite,
   microcline, natrolite, nepheline, pectolite, petarasite, polylithionite,
   pyrite, rhodochrosite, rinkite (mosandrite), sérandite,
   vesuvianite and wollastonite.
Distinguishing Features: Crystal habit and color.
Origin: Named in 1811 to reflect its sodium content.

CLASSIFICATION:

Dana System
# 76.2.3.1

Strunz Classification
# VIII/J.11-10

REFERENCES:
MinRec 21:339 (1990), Dana 8:1625-1626 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

MSH
¤¤¤

PE
--

AP
¤¤

MX
¤¤

SS
¤¤

MC
¤¤

HF
--

BR
¤¤

SX
¤¤

FR
¤¤

Legend

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

Sodalite crystals - click for larger pic
Sodalite crystals
"hackmanite" variety
4,5 x 3,7 cm
© Gilles Haineault

Sodalite crystals - click for larger pic
Sodalite crystals
© Quintin Wight