Stavelotite-(La) Mineral Data

General Stavelotite-(La) Information

Chemical Formula:

La3Mn++3Cu++(Mn+++,Fe+++,Mn++++)26(Si2O7)6O30

Composition:

Molecular Weight = 3,438.35 gm

Calcium 0.24 % Ca 0.34 % CaO

Lanthanum 7.38 % La 8.66 % La₂O₃

Cerium 0.39 % Ce 0.45 % Ce₂O₃

Magnesium 0.66 % Mg 1.09 % MgO

Scandium 0.99 % Sc 1.52 % Sc₂O₃

Titanium 0.27 % Ti 0.45 % TiO₂

Manganese 30.70 % Mn 32.67 % Mn₂O₃ / 4.98 % MnO₂

Aluminum 1.80 % Al 3.41 % Al₂O₃

Iron 9.44 % Fe 13.50 % Fe₂O₃

Cobalt 0.15 % Co 0.19 % CoO

Copper 1.74 % Cu 2.18 % CuO

Silicon 9.73 % Si 20.82 % SiO₂

Neodymium 3.00 % Nd 3.50 % Nd₂O₃

Oxygen 33.50 % O

______ ______

100.00 % 99.93 % = TOTAL OXIDE

Empirical Formula:

La_1.82Nd_0.71Ce_0.09Ca_0.2Sc_0.15Mn²⁺_2.99Cu_0.94Mn³⁺_0.05Mn³⁺_14.18Fe³⁺_5.81Al_2.29 Mn⁴⁺_1.97Mg_0.93Sc_0.6Ti_0.19Co_0.08Si_11.91O₇₂

Environment:

Minor accessory mineral in a quartz vein cross-cutting deep purple, highly oxidized manganiferous Ordovician phyllites.

IMA Status:

Approved IMA 2004 (Dana # Added)

Locality:

Stavelot Massif at Le Coreux, 1 km north of Salmchâteau along the western flanks of the Salm river valley, Ardennes, Belgium. Link to MinDat.org Location Data.

Name Origin:

Named for the Stavelot Massif in the Belgian Ardennes Mountains, and Stavelot, which is a historical town in eastern Belgium.

Synonym:

IMA2004-014

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Stavelotite-(La) Crystallography

Axial Ratios:

a:c = 1:2.89344

Cell Dimensions:

a = 11.525, c = 33.347, Z = 3; V = 3,835.92 Den(Calc)= 4.47

Crystal System:

Trigonal - PyramidalH-M Symbol (3) Space Group: P 3₁

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

By Intensity(I/I_o): 2.7232(1)(224 ), 1.6635(0.4)(600 ), 2.7789(0.4)(0.0.12 ), 5.446(0.31)(112 ), 2.3702(0.29)(228 )1.6887(0.28)(2.2.16 )3.1873(0.19)(033,303 )11.116(0.18)(003 ),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
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S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
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Bernhardt H J , Armbruster T , Fransolet A M , Schreyer W , European Journal of Mineralogy , 17 (2005) p.703-714, Stavelotite-(La), a new lanthanum-manganese-sorosilicate mineral from the Stavelot Massif, Belgium, Locality: Le Coreux, Salmchateau, Belgium

Physical Properties of Stavelotite-(La)

Cleavage:

None

Color:

Black.

Diaphaneity:

Opaque

Fracture:

Unknown - Minerals too small to observe fractures.

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Anhedral Grains - Granular minerals without the expression of crystal shapes

Luster:

Metallic

Optical Properties of Stavelotite-(La)

Optical Data:

Uniaxial (?).

RL Anisotrophism:

Very weak.

RL Bireflectance:

Weak to very weak.

RL Color:

Gray.

RL Pleochroism:

Very weak with weak brown internal reflections in oil.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Stavelotite-(La) in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
470 nm	13.60	14.40
546 nm	13.20	13.90
589 nm	13.00	13.70
650 nm	12.80	13.40

**Standardized Intensity (100%) Reflection Spectra of Stavelotite-(La) in Oil**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
470 nm	3.00	3.70
546 nm	2.90	3.50
589 nm	2.80	3.40
650 nm	2.70	3.20

**Calculated Relative Intensity Colors of Stavelotite-(La) in Air**
Relative Intensity	0%	70%	100%	140%	210%	280%	350%	420%	490%	560%	630%	680%
R₁
R₂

**Calculated Relative Intensity Colors of Stavelotite-(La) in Oil**
Relative Intensity	0%	100%	200%	300%	400%	500%	600%	700%	800%	900%	1000%
R₁
R₂

Calculated Properties of Stavelotite-(La)

Electron Density:

Bulk Density (Electron Density)=4.22 gm/cc
note: Specific Gravity of Stavelotite-(La) =4.47 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_{Stavelotite-(La)}= 64.68 barns/electron
U=PE_{Stavelotite-(La)} x r_electron= 272.75 barns/cc.

Radioactivity:

GRapi = 10,839.46 (Gamma Ray American Petroleum Institute Units)
Concentration of Stavelotite-(La) per GRapi unit = 92.26 (PPM)

Stavelotite-(La) is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.

**Estimated Radioactivity from Stavelotite-(La)** - weak
Specimen Size Weight/Volume (Sphere) *	Calculated Activity Becquerels (Bq)	Calculated Activity Curies (Ci)	Estimated Activity GR(api)	Estimated Exposure (mRem**)/hr If Held in Hand For One Hour
1000 gm / 7.53 cm	241,281	6.52E-06	10,839.46	3.56
100 gm / 3.50 cm	24,128	6.52E-07	1,083.95	0.36
10 gm / 1.62 cm	2,413	6.52E-08	108.39	0.04
1 gm / 7.53 mm	241	6.52E-09	10.84	0.00
0.1 gm / 3.50 mm	24	6.52E-10	1.08	0.00
0.01 gm / 1.62 mm	2	6.52E-11	0.11	0.00
0.001 gm / 0.75 mm	0	6.52E-12	0.01	0.00

Weight of pure Stavelotite-(La) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.47 gm/cc.*
Goverment Estimate of Average Annual Exposure ( 360 mRem) **
Note: 10 microsieverts/hr = 1 mRem/hr **
Max Permissable Adult Dose 50,000 mRem/yr (hands), 15,000 mRem/yr (eyes)
Lethal Dose LD(50) Exposure 400,000 to 500,000 mRem
Estimated Thorium Activity ( 0.54 % Th) From Sum REE Elements (10.77 % REE)

Stavelotite-(La) Classification

Dana Class:

55.04.04.01 (55)Sorosilicate Si2O7 Groups, Generally with No Additional Anions

(55.04)with cations in [8] and lower coordination

(55.04.04)Dana Group

55.04.04.01 Stavelotite-(La)! La3Mn3Cu(Mn,Fe,Mn)26(Si2O7)6O30 P 3₁ 3

Strunz Class:

09.BE.87 09 - SILICATES (Germanates)

09.B - Sorosilicates

09.BE -Si2O7 groups with additional anions;

09.BE.87 Stavelotite-(La)! La3Mn3Cu(Mn,Fe,Mn)26(Si2O7)6O30 P 3₁ 3

Other Stavelotite-(La) Information

References:

NAME( AmMin, v91, p1206) PHYS. PROP.(AmMin, v91, p1206) OPTIC PROP.(AmMin, v91, p1206)

See Also:

Links to other databases for Stavelotite-(La) :
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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Print or Cut-and-Paste your Stavelotite-(La) Specimen Label here :

Stavelotite-(La)

La3Mn++3Cu++(Mn+++,Fe+++,Mn++++)26(Si2O7)6O30
Dana No: 55.04.04.01 Strunz No: 09.BE.87
Locality:

Notes: