Micheelsenite Mineral Data

General Micheelsenite Information

Chemical Formula:

(Ca,Y)3Al[PO3OH,CO3](CO3)(OH)6•12(H2O)

Composition:

Molecular Weight = 667.02 gm

Calcium 12.02 % Ca 16.81 % CaO

Dysprosium 2.44 % Dy 2.80 % Dy₂O₃

Yttrium 13.33 % Y 16.93 % Y₂O₃

Aluminum 3.64 % Al 6.88 % Al₂O₃

Phosphorus 3.25 % P 7.45 % P₂O₅

Hydrogen 4.64 % H 41.46 % H₂O

Carbon 2.16 % C 7.92 % CO₂

Oxygen 58.53 % O

______ ______

100.00 % 100.24 % = TOTAL OXIDE

Empirical Formula:

Ca₂YDy_0.1Al_0.9(PO₃OH)_0.7(CO₃)_1.2(OH)₆•12(H₂O)

Environment:

Late-stage hydrothermal product and in pegmatites, hornfels, marble zenoliths, and silicate cavities. Ettringite group, structure

IMA Status:

Approved IMA 1999 (Dana # Added)

Locality:

Mont Saint-Hilaire, Quebec Canada and the Nanna pegmatite, Narsaarsuup Qaava, South Greenland. Link to MinDat.org Location Data.

Name Origin:

Named for H. I. Micheelsen (1931-), of the University of Copenhagen, Denmark.

Synonym:

IMA1999-033

Micheelsenite Image

Images:

Micheelsenite

Comments: Cotton ball bundles of white, fibrous michellsenite crystals on albite.
Location: Mont Saint-Hilaire, Rouville Co., Quebec, Canada. Scale: Sample size 4 x 3 x 1.5 cm.
© Tom Loomis / Dakota Matrix

Micheelsenite Crystallography

Axial Ratios:

a:c = 1:0.97118

Cell Dimensions:

a = 10.828, c = 10.516, Z = 2; V = 1,067.77 Den(Calc)= 2.07

Crystal System:

Hexagonal - Pyramidal H-M Symbol (6) Space Group: P 6₃

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

By Intensity(I/I_o): 9.38(1)(100), 2.491(0.8)(213), 4.59(0.7)(102),2.143(0.65)(223,402), 3.36(0.55)(211), 3.77(0.5)(112),

Physical Properties of Micheelsenite

Cleavage:

{100} Good, {001} Good

Color:

Colorless, White.

Density:

2.15

Diaphaneity:

Transparent to Translucent

Fracture:

Brittle - Splintery - Brittle fracture leaving splintery fragments.

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

Fibrous - Crystals made up of fibers.

Habit:

Spherical - Spherical, rounded aggregates.

Hardness:

3.5-4 - Copper Penny-Fluorite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Micheelsenite

Gladstone-Dale:

CI meas= 0.048 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.011 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.25,KPDmeas= 0.2407,KC= 0.2528
Ncalc = 1.52 - 1.54

Optical Data:

Uniaxial (-), e=1.503, w=1.532, bire=0.0290.

Calculated Properties of Micheelsenite

Electron Density:

Bulk Density (Electron Density)=2.12 gm/cc
note: Specific Gravity of Micheelsenite =2.07 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_{Micheelsenite}= 34.37 barns/electron
U=PE_{Micheelsenite} x r_electron= 72.71 barns/cc.

Radioactivity:

GRapi = 2,656.20 (Gamma Ray American Petroleum Institute Units)
Concentration of Micheelsenite per GRapi unit = 376.48 (PPM)

**Estimated Radioactivity from Micheelsenite** - mild
Specimen Size Weight/Volume (Sphere) *	Calculated Activity Bequerols (Bq)	Calculated Activity Curies (Ci)	Estimated Activity GR(api)	Estimated Exposure (mRem**)/hr If Held in Hand For One Hour
1000 gm / 9.74 cm	54,571	1.47E-06	2,656.20	0.87
100 gm / 4.52 cm	5,457	1.47E-07	265.62	0.09
10 gm / 2.10 cm	546	1.47E-08	26.56	0.01
1 gm / 9.74 mm	55	1.47E-09	2.66	0.00
0.1 gm / 4.52 mm	5	1.47E-10	0.27	0.00
0.01 gm / 2.10 mm	1	1.47E-11	0.03	0.00
0.001 gm / 0.97 mm	0	1.47E-12	0.00	0.00

Weight of pure Micheelsenite in grams (gm) and Calculated Diameter of a Sphere with a Density of 2.07 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 ( 0.12 % Th) From Sum REE Elements ( 2.44 % REE)

Micheelsenite Classification

Dana Class:

43.05.22.01 (43)Compound Phosphates, etc.

(43.05)(Hydrated Compound Anions With Hydroxyl or Halogen)

(43.05.22)Dana Group

43.05.22.01 Micheelsenite! (Ca,Y)3Al[PO3OH,CO3](CO3)(OH)6•12(H2O) P 6₃ 6

Strunz Class:

08.DO.30 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

08.DO -With CO3, SO4, SiO4

08.DO.30 Micheelsenite! (Ca,Y)3Al[PO3OH,CO3](CO3)(OH)6•12(H2O) P 6₃ 6

Other Micheelsenite Information

References:

NAME( AmMin, Vol 87, p 356) PHYS. PROP.(AmMin, Vol 87, p 356) OPTIC PROP.(AmMin, Vol 87, p 356)

See Also:

Links to other databases for Micheelsenite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Athena
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

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Micheelsenite

(Ca,Y)3Al[PO3OH,CO3](CO3)(OH)6•12(H2O)
Dana No: 43.05.22.01 Strunz No: 08.DO.30
Locality:

Notes:

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