Khmaralite Mineral Data

Khmaralite Mineral Data

[Express Minerals] [Minerals for Sale] [About Us] [En EspaÃƒï¿½Ã‚Â±ol] [Mineral Gallery]
Fabre Minerals - Europe's first Internet mineral dealer, on the web since 1996

General Khmaralite Information

Chemical Formula:

(Mg,Al,Fe)16(Al,Si,Be)12O40

Composition:

Molecular Weight = 1,401.96 gm

Magnesium 16.64 % Mg 27.60 % MgO

Beryllium 1.03 % Be 2.85 % BeO

Aluminum 23.09 % Al 43.64 % Al₂O₃

Iron 6.37 % Fe 8.20 % FeO

Silicon 7.21 % Si 15.43 % SiO₂

Oxygen 45.65 % O

______ ______

100.00 % 97.72 % = TOTAL OXIDE

Empirical Formula:

Mg_9.6Al_4.8Fe²⁺_1.6Al_7.2Si_3.6Be_1.6O₄₀

Environment:

In a single specimen of a pegmatite. A member of the sapphirine group

IMA Status:

Approved IMA 1998 (Dana # Added)

Locality:

From "Zircon Point,", Khmara Bay, Enderby Land, Antarctica. Link to MinDat.org Location Data.

Name Origin:

For the locality, which was named in honor of Ivan Fedorovich Khmara (1936-1956), a tractor driver who perished in Antarctica.

Synonym:

ICSD 87692

IMA1998-027

Search for Khmaralite Images

Images:

Image not yet available on Webmineral.com

Try searching images.google.com or Mindat Picture Gallary for mineral pictures. Caution: The images retrieved may not be appropriate.

Khmaralite Crystallography

Axial Ratios:

a:b:c =1.3081:1:0.7831

Cell Dimensions:

a = 18.8, b = 14.371, c = 11.254, Z = 4; beta = 125.53° V = 2,474.43 Den(Calc)= 3.76

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 2₁/c

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

By Intensity(I/I_o): 2.4446(1), 2.0106(0.85), 2.01(0.61),2.826(0.45), 2.4385(0.44), 2.3405(0.43),

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

Barbier J , Grew E S , Moore P B , Su S-C , American Mineralogist , 84 (1999) p.1650-1660, Khmaralite, a new beryllium-bearing mineral related to sapphirine:, A superstructure resulting from partial ordering of Be, Al and Si on, tetrahedral sites

Physical Properties of Khmaralite

Cleavage:

None

Color:

Very dark green.

Diaphaniety:

Transparent

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Foliated - Two dimensional platy forms.

Habit:

Tabular - Form dimensions are thin in one direction.

Hardness:

7 - Quartz

Luster:

Vitreous (Glassy)

Streak:

grayish green

Optical Properties of Khmaralite

Gladstone-Dale:

CI calc= 0.022 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1956,KC= 0.1999

Optical Data:

Biaxial (-), a=1.725, b=1.74, g=1.741, bire=0.0160, 2V(Calc)=28, 2V(Meas)=34. Dispersion r > v strong.

Calculated Properties of Khmaralite

Electron Density:

r_electron=3.70 gm/cc
note: r_Khmaralite=3.76 gm/cc.

Fermion Index

Fermion Index = 0.03186
Boson Index = 0.96814

Photoelectric:

PE_Khmaralite= 3.22 barns/electron
U=PE_Khmaralite x r_electron= 11.92 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Khmaralite is Not Radioactive

Khmaralite Classification

Dana Class:

69.2.1b.3 (69)Inosilicate Chains with Side Branches or Loops

(69.2)with P>2

(69.2.1b)Aenigmatite and related species (Sapphirine subgroup)

69.2.1b.1 Sapphirine (Mg,Al)8(Al,Si)6O20 P1 1

69.2.1b.2 Surinamite (Mg,Fe)3Al4BeSi3O16 P 2₁/n 2/m

69.2.1b.3 Khmaralite ! (Mg,Al,Fe)16(Al,Si,Be)12O40 P 2₁/c 2/m

Strunz Class:

VIII/F.15-15 VIII - Silicates

VIII/F - Inosilicates (chain and band) modified double chains

VIII/F.15 - Sapphirine - Surinamite series

VIII/F.15-10 Sapphirine (Mg,Al)8(Al,Si)6O20 P1 1

VIII/F.15-15 Khmaralite (Mg,Al,Fe)16(Al,Si,Be)12O40 P 2₁/c 2/m

VIII/F.15-20 Surinamite (Mg,Fe)3Al4BeSi3O16 P 2₁/n 2/m

Other Khmaralite Information

References:

NAME( MinRec, Vol 31, No 4) PHYS. PROP.(MinRec, Vol 31, No 4) OPTIC PROP.(MinRec, Vol 31, No 4)

See Also:

Links to other databases for Khmaralite :
1 -Am. Min. Crystal Structure Database 2 -Athena 3 -Google Images 4 -Google Scholar 5 -MinDAT 6 -MinMax(Deutsch) 7 -MinMax(English) 8 -Mineralienatlas (Deutsch) 9 -QUT Mineral Atlas

Search for Khmaralite using:

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

Visit our Advertisers for Khmaralite :
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 Khmaralite Mineral Data :

Ask about Khmaralite 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 Khmaralite Specimen Label here :

Khmaralite

(Mg,Al,Fe)16(Al,Si,Be)12O40
Dana No: 69.2.1b.3 Strunz No: VIII/F.15-15
Locality:

Notes: