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Nepheline crystals - click for larger pic
Embedded nepheline crystals
Photo by Violet Anderson, Stitt specimen
© Royal Ontario Museum

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Nepheline
(Na,K)AlSiO4

     Nepheline is a common rock-forming mineral at MSH, it is far less abundant in crystal form.

PHYSICAL CHARACTERISTICS:

Color is usually gray, greenish gray or yellowish white.
Luster is greasy, to dull to silky.
Diaphaneity is transparent to translucent.
Crystal System is orthorhombic; P63.
Crystal Habits include short hexagonal prisms to 4cm terminated
   by pinacoids; and crystalline masses to 2cm.
Cleavage {100} and {001} are indistinct.
Fracture is subconchoidal.
Hardness is 5.5 - 6.
Specific Gravity is approximately 2.5 g/cm3.
Streak is white.
Associated Minerals include aegirine, albite, amphibole group,
   analcime, ancylite, catapleiite, eudialyte, fluorapatite, gonnardite,
   microcline, natrolite, pectolite, rhodochrosite, rinkite (mosandrite)
   and sodalite.
Distinguishing Features: Crystal habit and luster.
Origin: Named in 1800 from the Greek nephele, a cloud, alluding to
   its cloudy appearance when immersed in strong acids.

CLASSIFICATION:

Dana System
# 76.2.1.2

Strunz Classification
# VIII/J.02-10

REFERENCES:
MinRec 21:325-326 (1990), Dana 8:1619-1621 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

MSH
¤¤¤

PE
¤¤

AP
--

MX
--

SS
¤¤

MC
¤¤

HF
--

BR
--

SX
¤¤

FR
¤¤

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