Ruifrancoite Mineral Data

General Ruifrancoite Information

Chemical Formula:

Ca2([ ],Mn)2(Fe+++,Mn,Mg)4Be4(PO4)6(OH)4•6H2O

Composition:

Molecular Weight = 1,075.85 gm

Calcium 7.04 % Ca 9.85 % CaO

Magnesium 1.94 % Mg 3.22 % MgO

Manganese 6.28 % Mn 8.11 % MnO

Beryllium 3.35 % Be 9.30 % BeO

Aluminum 0.45 % Al 0.85 % Al₂O₃

Iron 11.84 % Fe 3.94 % FeO / 12.54 % Fe₂O₃

Phosphorus 17.27 % P 39.58 % P₂O₅

Hydrogen 1.41 % H 12.60 % H₂O

Oxygen 50.41 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca_1.89Mn²⁺_0.55Fe³⁺_1.69Mg_0.86Mn²⁺_0.68Fe²⁺_0.59Al_0.18Be₄(PO₄)₆(OH)_4.75(H₂O)_1.25�3.9(H₂O)

Environment:

Occurs as a late vug-filling product in a zoned, LCT-type granitic pegmatite. Roscherite group.

IMA Status:

Approved IMA 2005 (Dana # Added)

Locality:

Sapucaia mine, Minas Gerais, Brazil. Link to MinDat.org Location Data.

Name Origin:

Named for Rui Ribeiro Franco (b. 1916), in recognition of his outstanding contributions to Brazilian mineralogy and geology.

Synonym:

IMA2005-061a

Ruifrancoite Image

Images:

Ruifrancoite

Comments: Botryoidal reddish brown aggregates of ruifrancoite associated with cyrilovite, and yellowish white spheres of meurigite on white mica. (CanMin, v45:1263).
Location: Sapucaia mine, Galiléia, Minas Gerais, Brazil. Scale: See Image.
© Canadian Mineralogist

Ruifrancoite Crystallography

Axial Ratios:

a:b:c =1.3366:1:0.5549

Cell Dimensions:

a = 15.92, b = 11.91, c = 6.61, Z = 2; beta = 96.4° V = 1,245.49 Den(Calc)= 2.87

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/c

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

By Intensity(I/I_o): 5.943(1), 4.816(0.65), 3.169(0.44),9.485(0.44), 2.643(0.42), 2.777(0.41), 3.117(0.25), 3.065(0.22),

Physical Properties of Ruifrancoite

Cleavage:

{100} Perfect, {010} Good

Color:

Reddish brown.

Density:

2.88

Diaphaneity:

Transparent

Fracture:

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

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

Botryoidal - "Grape-like" rounded forms (e.g.. malachite).

Habit:

Lath - Shaped like a small, thin plaster lath, tabular (rectangular) in shape.

Hardness:

4.5 - Between Fluorite and Apatite

Streak:

orange brown

Optical Properties of Ruifrancoite

Gladstone-Dale:

CI meas= -0.015 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.019 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2337,KPDmeas= 0.2329,KC= 0.2294
Ncalc = 1.66

Optical Data:

Biaxial (+), a=1.665, b=1.665, g=1.682, bire=0.0170, 2V(Calc)=0, 2V(Meas)=0-10. Dispersion r > v very strong.

Calculated Properties of Ruifrancoite

Electron Density:

Bulk Density (Electron Density)=2.85 gm/cc
note: Specific Gravity of Ruifrancoite =2.88 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_Ruifrancoite= 6.87 barns/electron
U=PE_Ruifrancoite x rElectron Density= 19.58 barns/cc.

Radioactivity:

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

Ruifrancoite Classification

Dana Class:

42.07.07.08 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen

(42.07)where (AB)5 (XO4)3 Zq � x(H2O)

(42.07.07)Roscherite group

42.07.07.01 Roscherite Ca(Mn,Fe)5Be4(PO4)6(OH)4•6(H2O) C1 1

42.07.07.03 Zanazziite Ca2(Mg,Fe)(Mg,Fe,Al,Mn,Fe)4Be4(PO4)6(OH)4•6(H2O) C 2/c 2/m

42.07.07.04 Greifensteinite! Ca2Be4(Fe,Mn)5(PO4)6(OH)4•6(H2O) C 2/c 2/m

42.07.07.05 Atencioite! Ca2Fe[]Mg2Fe2Be4(PO4)6(OH)4•6H2O P1 1

42.07.07.06 Guimaraesite Ca2(Zn,Mg,Fe)5Be4(PO4)6(OH)4•6H2O C 2/c 2/m

42.07.07.07 Footemineite! Ca2MnMn2Mn2Be4(PO4)6(OH)4•6H2O P1 1

42.07.07.08 Ruifrancoite! Ca2([],Mn)2(Fe,Mn,Mg)4Be4(PO4)6(OH)4•6H2O C 2/c 2/m

Strunz Class:

08.DA.10 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

08.DA -With small (and occasionally larger) cations

08.DA.10 Roscherite Ca(Mn,Fe)5Be4(PO4)6(OH)4•6(H2O) C1 1

08.DA.10 Zanazziite Ca2(Mg,Fe)(Mg,Fe,Al,Mn,Fe)4Be4(PO4)6(OH)4•6(H2O) C 2/c 2/m

08.DA.10 Footemineite! Ca2MnMn2Mn2Be4(PO4)6(OH)4•6H2O P1 1

08.DA.10 Atencioite! Ca2Fe[]Mg2Fe2Be4(PO4)6(OH)4•6H2O P1 1

08.DA.10 Greifensteinite! Ca2Be4(Fe,Mn)5(PO4)6(OH)4•6(H2O) C 2/c 2/m

08.DA.10 Ruifrancoite! Ca2([],Mn)2(Fe,Mn,Mg)4Be4(PO4)6(OH)4•6H2O C 2/c 2/m

08.DA.10 Guimaraesite Ca2(Zn,Mg,Fe)5Be4(PO4)6(OH)4•6H2O C 2/c 2/m

Other Ruifrancoite Information

References:

NAME( CanMin, v45:1263) PHYS. PROP.(CanMin, v45:1263) OPTIC PROP.(CanMin, v45:1263)

See Also:

Links to other databases for Ruifrancoite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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Ruifrancoite

Ca2([ ],Mn)2(Fe+++,Mn,Mg)4Be4(PO4)6(OH)4•6H2O
Dana No: 42.07.07.08 Strunz No: 08.DA.10
Locality:

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