Magnesio-axinite Mineral Data

Magnesio-axinite Mineral Data

General Magnesio-axinite Information

Chemical Formula:

Ca2MgAl2BO3Si4O12(OH)

Composition:

Molecular Weight = 538.57 gm

Calcium 14.88 % Ca 20.82 % CaO

Magnesium 4.51 % Mg 7.48 % MgO

Aluminum 10.02 % Al 18.93 % Al₂O₃

Silicon 20.86 % Si 44.62 % SiO₂

Boron 2.01 % B 6.46 % B₂O₃

Hydrogen 0.19 % H 1.67 % H₂O

Oxygen 47.53 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₂MgAl₂(BO₃)Si₄O₁₂(OH)

Environment:

Contact metamorphic, hydrothermal, and alpine vein rocks.

IMA Status:

Approved IMA 1975

Locality:

Tanzania. Link to MinDat.org Location Data.

Name Origin:

From the Greek acine - "axe" in allusion to the acute shape of typical crystals and the Greek, "Magnesia" a district in Thessaly in reference to the Mg in the chemical formula.

Synonym:

Axinite

Magnesio-axinite Image

Images:

Magnesio-axinite

Comments: Cinnamon brown crystal of "axinite" (probably magnesio-axinite).
Location: El Fenomino Tungsten Mine, Northern Baja Californa, Mexico. Scale: Crystal size 2 cm.
© Dave Barthelmy

Magnesio-axinite Crystallography

Axial Ratios:

a:b:c =0.9757:1:0.7778

Cell Dimensions:

a = 8.933, b = 9.155, c = 7.121, Z = 2; alpha = 102.59°, beta = 98.28°, gamma = 88.09° V = 562.13 Den(Calc)= 3.18

Crystal System:

Triclinic - PedialH-M Symbol (1) Space Group: P1

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

By Intensity(I/I_o): 2.796(1), 3.139(0.65), 3.44(0.65),

Forms:

Mouse
Dbl Clk - Start-Stop Rotation
RMB - Cycle Display Modes
Drag1 - Manipulate Crystal
Drag2 - Resize
Keyboard
S - Stereo
I - Indicies
<space> - Start-Stop Rotation
F - Fit to Screen
M - Menu
Help on Above

Forms: [ 1 1 1] [ 1 1 1] [ 1 0 0] [ 1 1 0] [ 2 0 1] [ 1 1 0]

Warning: this large pop-up is very compute intensive and may not work well with some computers.

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

Andreozzi G B , Lucchesi S , Graziani G , European Journal of Mineralogy , 12 (2000) p.1185-1194, Structural study of magnesioaxinite and its crystal-chemical relations, with axinite-group minerals

Physical Properties of Magnesio-axinite

Cleavage:

[100] Distinct, [001] Poor, [110] Poor

Color:

Brown, Purplish blue, Gray, Greenish yellow.

Density:

3.27 - 3.29, Average = 3.28

Diaphaniety:

Translucent to transparent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Lamellar - Thin laminae producing a lamellar structure.

Habit:

Massive - Granular - Common texture observed in granite and other igneous rock.

Hardness:

6.5-7 - Pyrite-Quartz

Luminescence:

Fluorescent.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Magnesio-axinite

Gladstone-Dale:

CI meas= 0.003 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.029 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2164,KPDmeas= 0.2098,KC= 0.2103

Optical Data:

Biaxial (-), a=1.672-1.693, b=1.677-1.701, g=1.681-1.704, bire=0.0090-0.0110, 2V(Calc)=62-82, 2V(Meas)=69-87. Dispersion strong, r < v.

Pleochroism (x):

colorless, yellow, light brown, yellow brown, or pale green.

Pleochroism (y):

colorless, deep yellow, deep blue, pale violet, or violet.

Pleochroism (z):

colorless, pale green, olive yellow, brown, or dark violet.

Calculated Properties of Magnesio-axinite

Electron Density:

r_electron=3.26 gm/cc
note: r_{Magnesio-axinite}=3.28 gm/cc.

Fermion Index

Fermion Index = 0.01867
Boson Index = 0.98133

Photoelectric:

PE_{Magnesio-axinite}= 3.05 barns/electron
U=PE_{Magnesio-axinite} x r_electron= 9.95 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Magnesio-axinite is Not Radioactive

Magnesio-axinite Classification

Dana Class:

56.2.2.2 (56)Sorosilicate Si2O7 Groups and O, OH, F. and H2O

(56.2)with cations in [4] and/or >[4] coordination

(56.2.2)Axinite group

56.2.2.1 Ferroaxinite Ca2FeAl2BO3Si4O12(OH) P1 1

56.2.2.2 Magnesio-axinite Ca2MgAl2BO3Si4O12(OH) P1 1

56.2.2.3 Manganaxinite Ca2MnAl2BO3Si4O12(OH) P1 1

56.2.2.4 Tinzenite (Ca,Mn,Fe)3Al2BO3Si4O12(OH) P1 1

Strunz Class:

VIII/E.06-10 VIII - Silicates

VIII/E - Cyklosilicates, quadruplet rings [Si4O11]8-

VIII/E.06 - Axinite group, Magnesio-axinite - Ashburtonite series

VIII/E.06-10 Magnesio-axinite Ca2MgAl2BO3Si4O12(OH) P1 1

VIII/E.06-20 Ferroaxinite Ca2FeAl2BO3Si4O12(OH) P1 1

VIII/E.06-30 Manganaxinite Ca2MnAl2BO3Si4O12(OH) P1 1

VIII/E.06-40 Tinzenite (Ca,Mn,Fe)3Al2BO3Si4O12(OH) P1 1

VIII/E.06-50 Papagoite CaCuAlSi2O6(OH)3 C 2/m 2/m

VIII/E.06-60 Ashburtonite HPb4Cu4Si4O12(HCO3)4(OH)4Cl I 4/m 4/m

Other Magnesio-axinite Information

References:

NAME( Duda&Rejl90) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Heinrich65)

See Also:

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

Search for Magnesio-axinite using:

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

Visit our Advertisers for Magnesio-axinite :

AA Mineral Specimens

B & L Fine Minerals

Dan Weinrich Fine Minerals

Dan Weinrich Auctions

John Betts Fine Minerals

Mason's Minerals

Mineral News

Mineral of the Month Club

MineralsWeb Fine Minerals

The GeoZone

Wrights Rock Shop

Translate Magnesio-axinite Mineral Data :

Ask about Magnesio-axinite 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 Magnesio-axinite Specimen Label here :

Magnesio-axinite

Ca2MgAl2BO3Si4O12(OH)
Dana No: 56.2.2.2 Strunz No: VIII/E.06-10
Locality:

Notes: