Mullite Mineral Data

Mullite Mineral Data +

[Current Minerals] [Order Status] [Policies] [e-Bay Items]
B & L Minerals, Fine Mineral specimens for sale for collectors of all levels

General Mullite Information

Chemical Formula:

Al(4+2x)Si(2-2x)O(10-x) where x =0.17 to 0.59

Composition:

Molecular Weight = 319.54 gm

Aluminum 38.00 % Al 71.79 % Al₂O₃

Silicon 13.18 % Si 28.21 % SiO₂

Oxygen 48.82 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Al_4.5Si_1.5O_9.75

Environment:

Remelted Tertiary-aged clays.

IMA Status:

Valid Species (Pre-IMA) 1924

Locality:

Isle of Mull, Scotland, England. Link to MinDat.org Location Data.

Name Origin:

Named after its locality.

Mullite Image

Images:

Mullite

Comments: Opaque white mullite masses with mica.
Location: Nijar, Almeria, Andalucia, Spain. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Images:

Mullite

Comments: Surface of a kaolinite stratum altered to white mullite by a prehistoric coal-seam-fire..
Location: Mt. Wingen (Burning Mountain), NSW, Australia. Scale: Picture size 6x4 cm.
© Dave Barthelmy

Mullite Crystallography

Axial Ratios:

a:b:c =0.9865:1:0.3757

Cell Dimensions:

a = 7.5785, b = 7.6817, c = 2.8864, Z = 1; V = 168.03 Den(Calc)= 3.16

Crystal System:

Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: Pbam

$Help on X Ray Diffraction:$ X Ray Diffraction:

By Intensity(I/I_o): 3.39(1), 3.428(0.95), 2.206(0.6),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Angel R J , Prewitt C T , American Mineralogist , 71 (1986) p.1476-1482, Crystal structure of mullite: A re-examination of the average structure

View Additional jPOWD Structure files for Mullite
[1] [10] [11] [2] [3] [4] [5] [6] [7] [8] [9]

Physical Properties of Mullite

Cleavage:

[010] Good

Color:

Colorless, Violet, Yellow, White, Light pink.

Density:

3 - 3.1, Average = 3.05

Diaphaniety:

Transparent to translucent

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Crystalline - Fine - Occurs as well-formed fine sized crystals.

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Hardness:

6-7 - Orthoclase-Quartz

Luminescence:

None.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Mullite

Gladstone-Dale:

CI meas= -0.035 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.001 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2071,KPDmeas= 0.2146,KC= 0.2073

Optical Data:

Biaxial (+), a=1.642-1.653, b=1.644-1.655, g=1.654-1.679, bire=0.0120-0.0260, 2V(Calc)=34-50, 2V(Meas)=20-50. Dispersion r > v.

Pleochroism (x):

colorless or colorless.

Pleochroism (y):

colorless or colorless.

Pleochroism (z):

colorless or rose.

Calculated Properties of Mullite

Electron Density:

r_electron=3.12 gm/cc
note: r_Mullite=3.16 gm/cc.

Fermion Index

Fermion Index = 0.00639
Boson Index = 0.99361

Photoelectric:

PE_Mullite= 1.62 barns/electron
U=PE_Mullite x r_electron= 5.04 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Mullite is Not Radioactive

Mullite Classification

Dana Class:

52.2.2a.2 (52)Nesosilicate Insular SiO4 Groups and O, OH, F, and H2O

(52.2)with cations in [4] and >[4] coordination

(52.2.2a)Al2SiO5 (Sillimanite subgroup)

52.2.2a.1 Sillimanite Al2SiO5=Al[6]Al[4]OSiO4 P nma 2/m 2/m 2/m

52.2.2a.2 Mullite Al(42x)Si(2-2x)O(10-x)wherex=0.17to0.59 Pbam 2/m 2/m 2/m

Strunz Class:

VIII/B.02-50 VIII - Silicates

VIII/B - Nesosubsilicates, with anions unfamiliar to tetraheders, cations of octahedral and tetrahedral orientation [4/6]

VIII/B.02 - Disthene series

VIII/B.02-10 Sillimanite Al2SiO5=Al[6]Al[4]OSiO4 P nma 2/m 2/m 2/m

VIII/B.02-20 Andalusite Al2SiO5=Al[6]Al[5]OSiO4 Pnnm 2/m 2/m 2/m

VIII/B.02-30 Kanonaite (Mn,Al)AlSiO5 Pnnm 2/m 2/m 2/m

VIII/B.02-40 Kyanite Al2SiO5=Al[6]Al[6]OSiO4 P1 1

VIII/B.02-50 Mullite Al(42x)Si(2-2x)O(10-x)wherex=0.17to0.59 Pbam 2/m 2/m 2/m

VIII/B.02-60 Yoderite Mg2(Al,Fe)6Si4O18(OH)2 P 2₁ 2

VIII/B.02-70 Topaz Al2SiO4(F,OH)2 Pbnm 2/m 2/m 2/m

Other Mullite Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Dana8) OPTIC PROP.(Heinrich65)

Search for Mullite using:

[ALTAVISTA] [AOL] [About.com] [All-The-Web] [HotBot] [Ixquick] [LookSmart] [MAMMA] [MSN.COM] [Netscape] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Mullite :
AA Mineral Specimens
B and L Minerals
Dan Weinrich Fine Minerals
Dan Weinrich Auctions
e-Rocks Auctions
Excalibur Minerals
Exceptional Minerals
Fabre Minerals
Greenside Minerals
John Betts Fine Minerals
Masons Minerals
Minernet.it
Mineral News
Mineral of the Month Club
MineralsWeb Fine Minerals
Rockshop.cz Kalat Fine Minerals
T G Fine Minerals
Wrights Rock Shop

Translate Mullite Mineral Data :

Ask about Mullite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

Print or Cut-and-Paste your Mullite Specimen Label here :

Mullite

Al(4+2x)Si(2-2x)O(10-x) where x =0.17 to 0.59
Dana No: 52.2.2a.2 Strunz No: VIII/B.02-50
Locality:

Notes: