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

Astrophyllite crystals - click for larger pic
Astrophyllite crystals
© Stephan Wolfsried

Astrophyllite crystals - click for larger pic
Astrophyllite crystals
© Elmar Lackner

Astrophyllite crystals - click for larger pic
Astrophyllite crystals
© Giovanni Fracarro

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Home > Mineral Descriptions > Astrophyllite - (4 Photos)



Astrophyllite
(K,Na3(Fe+2,Mn)7Ti2Si8O24(O,OH)7

     Astrophyllite is one of the more common and conspicuous mineral species at Mont Saint-Hilaire. It can be found in the nepheline syenite in proximity to various pegmatitic structures, and rarely in hornfels, marble xenoliths and miarolitic cavities.

     It is practically identical in color and habit to kupletskite, with which it may be intimately associated, rendering visual identification unreliable.

PHYSICAL CHARACTERISTICS:

Color is medium to dark brown, reddish bronze or brownish red.
Luster is greasy to pearly.
Diaphaneity is transparent to translucent in small crystals, masses
   are opaque.
Crystal System is triclinic; A1.
Crystal Habits include well-formed sharp, tabular to bladed crystals to
   several cm in length. Bladed and acicular microcrystals may also be
   found.
Cleavage: {001} is perfect and {100} is poor.
Fracture is uneven.
Hardness is 3.
Specific Gravity is approximately 3.2 g/cm3.
Streak is brown.
Associated Minerals include chkalovite, erdite, kogarkoite, makatite,
   natrophosphate, rasvumite, revdite, sazhinite-(Ce), sidorenkite,
   thalcusite, tugtupite and vitusite-(Ce).
Distinguishing Features: Crystal habit. Bronzy appearance.
Origin: From the Greek astron, star and phyllon, a leaf; alluding to
   its high luster and foliate habit. Described in 1854.

CLASSIFICATION:

Dana System
# 69.1.1.1

Strunz Classification
# VIII/G.12-40

REFERENCES:
MinRec 21:297-298 (1990), Dana 8:1382-1383 (1997)

DISTRIBUTION AND RARITY AT MONT SAINT-HILAIRE:

MSH
¤¤¤

PE
¤¤

AP
¤¤

MX
--

SS
--

MC
¤¤

HF
¤¤

BR
--

SX
¤¤

FR
¤¤

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