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C o n t r i b u t e
● H e l p ● L e a r n t o e d i t ● C o m m u n i t y p o r t a l ● R e c e n t c h a n g e s ● U p l o a d f i l e
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Search
A p p e a r a n c e
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P e r s o n a l t o o l s
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P a g e s f o r l o g g e d o u t e d i t o r s l e a r n m o r e ● C o n t r i b u t i o n s ● T a l k
( T o p )
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2 U s e s
3 G a l l e r y
4 S e e a l s o
5 R e f e r e n c e s
T o g g l e t h e t a b l e o f c o n t e n t s
S i l l i m a n i t e
3 2 l a n g u a g e s
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E d i t l i n k s
● A r t i c l e ● T a l k
E n g l i s h
● R e a d ● E d i t ● V i e w h i s t o r y
T o o l s
T o o l s
A c t i o n s
● R e a d ● E d i t ● V i e w h i s t o r y
G e n e r a l
● W h a t l i n k s h e r e ● R e l a t e d c h a n g e s ● U p l o a d f i l e ● S p e c i a l p a g e s ● P e r m a n e n t l i n k ● P a g e i n f o r m a t i o n ● C i t e t h i s p a g e ● G e t s h o r t e n e d U R L ● D o w n l o a d Q R c o d e ● W i k i d a t a i t e m
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A p p e a r a n c e
F r o m W i k i p e d i a , t h e f r e e e n c y c l o p e d i a
Sillimanite Category Nesosilicate Formula (repeating unit) Al 2 5 IMA symbol Sil[1] Strunz classification 9.AF.05 Dana classification 52.02.02a.01 Crystal system Orthorhombic Crystal class Dipyramidal (mmm) H-M symbol : (2/m 2/m 2/m) Space group Pbnm Unit cell a = 7.47 Å , b = 7.66 Å 4 Color Colourless or white to grey, also brown, yellow, yellow-green, grey-green, blue-green, blue; colourless in thin section Crystal habit Prismatic crystals, fibrous, acicular Cleavage {010} perfect Fracture Splintery Tenacity Tough Mohs scale hardness 7 Luster Vitreous to subadamantine, silky Streak White Diaphaneity Transparent to translucent Specific gravity 3.24 Optical properties Biaxial (+) Refractive index n α = 1.653 – 1.661 nβ = 1.654 – 1.670 nγ = 1.669 – 1.684Birefringence δ = 0.020 – 0.022 Pleochroism Colourless to pale brown to yellow 2V angle 21–30° References [2] [3] [4] [5]
Phase diagram of Al2 5 aluminosilicates ).[6]
Sillimanite or fibrolite is an aluminosilicate mineral with the chemical formula Al 2 5 Benjamin Silliman (1779–1864). It was first described in 1824 for an occurrence in Chester, Connecticut .[4]
Occurrence
[ edit ]
Sillimanite or fibrolite is one of three aluminosilicate polymorphs , the other two being andalusite and kyanite . A common variety of sillimanite is known as fibrolite , so named because the mineral appears like a bunch of fibres twisted together when viewed in thin section or even by the naked eye. Both the fibrous and traditional forms of sillimanite are common in metamorphosed sedimentary rocks . It is an index mineral indicating high temperature but variable pressure. Example rocks include gneiss and granulite . It occurs with andalusite, kyanite, potassium feldspar , almandine , cordierite , biotite and quartz in schist , gneiss, hornfels and also rarely in pegmatites .[3] Dumortierite and mullite are similar mineral species found in porcelain .[7]
Sillimanite has been found in Brandywine Springs , New Castle County, Delaware . It was named by the State Legislature in 1977 as the state mineral of Delaware by the suggestion of the Delaware Mineralogical Society .[8]
Uses
[ edit ]
Natural sillimanite is used in the manufacture of high alumina refractories or 55–60% alumina bricks. However, it has mostly been replaced by the other aluminosilicate polymorphs, andalusite and kyanite, for this purpose.[9] [update] [10]
Gallery
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Silimanite crystal from
Sri Lanka
Fibrolite micrograph
See also
[ edit ]
References
[ edit ]
^ a b http://rruff.geo.arizona.edu/doclib/hom/sillimanite.pdf Handbook of Mineralogy
^ a b http://www.mindat.org/min-3662.html Mindat.org
^ MacKenzie, W. S.; Guilford, C. (1980). Atlas of rock-forming minerals in thin section 10 ISBN 0-582-45591-X
^ Whitney, D.L. (2002). "Coexisting andalusite, kyanite, and sillimanite: Sequential formation of three Al2 5 American Mineralogist . 87 4 ): 405–416. doi :10.2138/am-2002-0404 .
^ Klein, Cornelis and Cornelius S. Hurlbut, Jr., Manual of Mineralogy, 1985, Wiley 20th ed., p. 380 ISBN 0-471-80580-7
^ "Delaware State Mineral – Delaware Geological Survey" . Archived from the original on 2010-06-10. Retrieved 2009-12-19 .
^ Gilchrist, J.D. (1977). "Alumino-Silicate Refractories". Fuels, Furnaces and Refractories : 258–272. doi :10.1016/B978-0-08-020430-7.50027-X . ISBN 9780080204307
^ Ihlen, Peter M. (2000). "Utilisation of sillimanite minerals, their geology, and potential occurrences in Norway – an overview" (PDF) . Geological Survey of Norway Bulletin . 436 : 113. Retrieved 14 March 2022 .
R e t r i e v e d f r o m " https://en.wikipedia.org/w/index.php?title=Sillimanite&oldid=1223083680 " C a t e g o r i e s : ● A l u m i n i u m m i n e r a l s ● N e s o s i l i c a t e s ● O r t h o r h o m b i c m i n e r a l s ● M i n e r a l s i n s p a c e g r o u p 6 2 ● I n d u s t r i a l m i n e r a l s ● S y m b o l s o f D e l a w a r e H i d d e n c a t e g o r i e s : ● A r t i c l e s w i t h s h o r t d e s c r i p t i o n ● S h o r t d e s c r i p t i o n m a t c h e s W i k i d a t a ● A r t i c l e s c o n t a i n i n g p o t e n t i a l l y d a t e d s t a t e m e n t s f r o m 1 9 9 8 ● A l l a r t i c l e s c o n t a i n i n g p o t e n t i a l l y d a t e d s t a t e m e n t s
● T h i s p a g e w a s l a s t e d i t e d o n 9 M a y 2 0 2 4 , a t 1 9 : 5 2 ( U T C ) . ● T e x t i s a v a i l a b l e u n d e r t h e C r e a t i v e C o m m o n s A t t r i b u t i o n - S h a r e A l i k e L i c e n s e 4 . 0 ;
a d d i t i o n a l t e r m s m a y a p p l y . B y u s i n g t h i s s i t e , y o u a g r e e t o t h e T e r m s o f U s e a n d P r i v a c y P o l i c y . W i k i p e d i a ® i s a r e g i s t e r e d t r a d e m a r k o f t h e W i k i m e d i a F o u n d a t i o n , I n c . , a n o n - p r o f i t o r g a n i z a t i o n . ● P r i v a c y p o l i c y ● A b o u t W i k i p e d i a ● D i s c l a i m e r s ● C o n t a c t W i k i p e d i a ● C o d e o f C o n d u c t ● D e v e l o p e r s ● S t a t i s t i c s ● C o o k i e s t a t e m e n t ● M o b i l e v i e w
