Macfallite Mineral Data (original) (raw)

General Macfallite Information

Help on Chemical Formula: Chemical Formula:

Ca2(Mn+++,Al)3(SiO4)(Si2O7)(OH)3

Help on Composition: Composition:

Molecular Weight = 544.17 gm

Sodium 0.04 % Na 0.06 % Na2O

Calcium 14.95 % Ca 20.92 % CaO

Magnesium 0.40 % Mg 0.67 % MgO

Manganese 25.34 % Mn 36.41 % Mn2O3

Aluminum 1.34 % Al 2.53 % Al2O3

Vanadium 0.09 % V 0.14 % V2O3

Copper 0.35 % Cu 0.44 % CuO

Silicon 15.74 % Si 33.68 % SiO2

Hydrogen 0.58 % H 5.16 % H2O

Oxygen 41.16 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Help on Empirical Formula: Empirical Formula:

Ca2.03Na0.01Mn3+2.51Al0.27Mg0.09Cu0.03V3+0.01Si3.05O10.88(OH)3.12

Help on Environment: Environment:

Associated with other Mn-silicates.

Help on IMA Status: IMA Status:

Approved IMA 1979

Help on Locality: Locality:

Manganese Lake, Copper Harbor, Keweenaw County, Michigan, USA. Link to MinDat.org Location Data.

Help on Name Origin: Name Origin:

Named for Russell P. MacFall, a dedicated amateur mineralogist.

Help on Name Pronunciation: Name Pronunciation:

Macfallite + Pronunciation Say MACFALLITE

Help on Synonym: Synonym:

ICSD 1612

PDF 42-601

Macfallite Image

Click Here for Larger Macfallite Image in a New Browser Window Images:

Click Here for Larger Macfallite Image Macfallite Johnsenite-(Ce) Braunite-I Comments: Tiny - less than 1mm - maroon crystals of mcfallite suspended as inclusions in massive quartz along with larger spots of brown johnsenite-(Ce) and braunite. Location: Artur mine, Jaguaracu, Minas Gerais, Brazil.Scale: Overall 3 x 2.5 slab. © Tom Loomis / Dakota Matrix

Macfallite Crystallography

Help on Axial Ratios: Axial Ratios:

a:b:c =1.4754:1:1.6828

Help on Cell Dimensions: Cell Dimensions:

a = 8.959, b = 6.072, c = 10.218, Z = 2; beta = 110.75° V = 519.79 Den(Calc)= 3.48

Help on Crystal System: Crystal System:

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

Help on X Ray Diffraction: X Ray Diffraction:

By Intensity(I/Io): 3.399(1), 3.892(0.7), 2.962(0.5),

Click Here for Large Macfallite Structure Window Crystal Structure:

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Help on Above

| | Moore P B , Shen J , Araki T , American Mineralogist , 70 (1985) p.171-181, Crystal chemistry of the (M2)3+ phi2 sheet: Structural principles and crystal, structures of ruizite, macfallite and orientite | | ------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |

Physical Properties of Macfallite

Help on Cleavage: Cleavage:

{001} Perfect

Help on Color: Color:

Brown, Maroon, Reddish brown, Pink.

Help on Density: Density:

3.43

Help on Habit: Habit:

Acicular - Occurs as needle-like crystals.

Help on Habit: Habit:

Aggregates - Made of numerous individual crystals or clusters.

Help on Habit: Habit:

Twinning Common - Crystals are usually twinned.

Help on Hardness: Hardness:

5-5.5 - Apatite-Knife Blade

Help on Luster: Luster:

Vitreous - Silky

Help on Streak: Streak:

brown

Optical Properties of Macfallite

Help on Gladstone-Dale: Gladstone-Dale:

CI meas= 0.07 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.084 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2281,KPDmeas= 0.2314,KC= 0.2489
Ncalc = 1.85 - 1.87

Help on Optical Data: Optical Data:

Biaxial (-), a=1.773-1.775, b=1.795, g=1.81-1.815, bire=0.0370-0.0400, 2V(Calc)=78-88, 2V(Meas)=86.

Help on Pleochroism (x): Pleochroism (x):

colorless or yellow.

Help on Pleochroism (y): Pleochroism (y):

light brown or light brown.

Help on Pleochroism (z): Pleochroism (z):

brownish red or dark brown.

Calculated Properties of Macfallite

Help on Electron Density: Electron Density:

Bulk Density (Electron Density)=3.37 gm/cc
note: Specific Gravity of Macfallite =3.43 gm/cc.

Help on Fermion Index: Fermion Index:

Fermion Index = 0.0081559315
Boson Index = 0.9918440685

Help on Photoelectric: Photoelectric:

PEMacfallite = 9.10 barns/electron
U=PEMacfallite x rElectron Density= 30.63 barns/cc.

Help on Radioactivity: Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Macfallite is Not Radioactive

Macfallite Classification

Help on Dana Class: Dana Class:

58.02.03.02 (58)Sorosilicate Insular, Mixed, Single, and Larger Tetrahedral Groups

(58.02)with cations in [6] and higher coordination; single and double groups (n=1,2)

(58.02.03)Sursassite and related species

58.02.03.01 Sursassite Mn2Al3(SiO4)(Si2O7)(OH)3 P 21/m 2/m

58.02.03.02 Macfallite Ca2(Mn,Al)3(SiO4)(Si2O7)(OH)3 P 21/m 2/m

Help on Strunz Class: Strunz Class:

09.BG.15 09 - SILICATES (Germanates)

09.B - Sorosilicates

09.BG -Sorosilicates with mixed SiO4 and Si2O7 groups;

09.BG.15 Macfallite Ca2(Mn,Al)3(SiO4)(Si2O7)(OH)3 P 21/m 2/m

09.BG.15 Sursassite Mn2Al3(SiO4)(Si2O7)(OH)3 P 21/m 2/m

Other Macfallite Information

Help on References: References:

NAME( Dana8) PHYS. PROP.(Dana8, AmMin v93:1851) OPTIC PROP.(Dana8)

Help on See Also: See Also:

Links to other databases for Macfallite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - WWW-MINCRYST

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Ask about Macfallite here :
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Print or Cut-and-Paste your Macfallite Specimen Label here :

Macfallite

Ca2(Mn+++,Al)3(SiO4)(Si2O7)(OH)3
Dana No: 58.02.03.02 Strunz No: 09.BG.15
Locality:

Notes: