Dessauite Mineral Data

Dessauite Mineral Data +

General Dessauite Information

Chemical Formula:

(Sr,Pb)(Y,U)(Ti,Fe+++)20O38

Composition:

Molecular Weight = 1,856.57 gm

Strontium 3.54 % Sr 4.19 % SrO

Yttrium 3.35 % Y 4.26 % Y₂O₃

Uranium 3.85 % U 4.36 % UO₂

Titanium 38.68 % Ti 64.54 % TiO₂

Iron 15.04 % Fe 21.50 % Fe₂O₃

Lead 2.79 % Pb 3.01 % PbO

Oxygen 32.75 % O

______ ______

100.00 % 101.85 % = TOTAL OXIDE

Empirical Formula:

Sr_0.75Pb_0.25Y_0.7U_0.3Ti₁₅Fe³⁺₅O₃₈

Environment:

In calcite veins within dolomite. A member of the Crichtonite group.

IMA Status:

Approved IMA 1997 (Dana # Added)

Locality:

The Buca della Vena mine, Apuan Alps, near the town of Stazzema, northern Tuscany, Italy. Link to MinDat.org Location Data.

Name Origin:

For Gabor Dessau (1907-1983), professor of ore mineralogy at the University of Pisa, Italy.

Synonym:

ICSD 77505

IMA1994-057

Romanite

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Dessauite Crystallography

Axial Ratios:

a:c = 1:2.01454

Cell Dimensions:

a = 10.385, c = 20.921, Z = 6; V = 1,954.01 Den(Calc)= 9.47

Crystal System:

Trigonal - RhombohedralH-M Symbol ( 3) Space Group: P 3

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Physical Properties of Dessauite

Cleavage:

None

Color:

Black.

Density:

4.68

Diaphaniety:

Opaque

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Tabular - Form dimensions are thin in one direction.

Hardness:

6.5-7 - Pyrite-Quartz

Luster:

Metallic

Streak:

black

Optical Properties of Dessauite

Optical Data:

NCalc= 4.25 - from Gladstone-Dale relationship (KC = 0.343) where Ncalc=Dcalc*KC+1
NCalc= 2.61 - from Gladstone-Dale relationship (KC = 0.343) where Ncalc=Dmeas*KC+1

RL Anisotrophism:

Weak.

RL Bireflectance:

Low.

RL Color:

Ash gray with pale blue tones.

RL Pleochroism:

Very weak.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Dessauite in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
470 nm	17.30	17.70
546 nm	16.60	17.10
589 nm	16.10	16.60
650 nm	16.00	16.50

**Standardized Intensity (100%) Reflection Spectra of Dessauite in Oil**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
470 nm	5.60	6.00
546 nm	5.00	5.50
589 nm	4.80	5.30
650 nm	4.60	5.10

**Calculated Relative Intensity Colors of Dessauite in Air**
Relative Intensity	0%	60%	100%	120%	180%	240%	300%	360%	420%	480%	540%	550%
R₁
R₂

**Calculated Relative Intensity Colors of Dessauite in Oil**
Relative Intensity	0%	100%	200%	300%	400%	500%	600%	700%	800%	900%	1000%
R₁
R₂

Calculated Properties of Dessauite

Electron Density:

r_electron=8.85 gm/cc
note: r_Dessauite=9.47 gm/cc.

Fermion Index

Fermion Index = 0.06228
Boson Index = 0.93772

Photoelectric:

PE_Dessauite= 158.61 barns/electron
U=PE_Dessauite x r_electron=1,404.30 barns/cc.

Radioactivity:

GRapi = 306,521.28 (Gamma Ray American Petroleum Institute Units)

Dessauite is Radioactive as defined in 49 CFR 173.403. Greater than 70 Bq / gram.

Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 10 cm box) 99.23 ± 24.81 grams of pure Dessauite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 9923.2 ±2480.8 grams of pure Dessauite .

**Estimated Radioactivity from Dessauite** - strong
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 / 5.86 cm	6,884,805	1.86E-04	306,521.28	100.77
100 gm / 2.72 cm	688,481	1.86E-05	30,652.13	10.08
10 gm / 1.26 cm	68,848	1.86E-06	3,065.21	1.01
1 gm / 5.86 mm	6,885	1.86E-07	306.52	0.10
0.1 gm / 2.72 mm	688	1.86E-08	30.65	0.01
0.01 gm / 1.26 mm	69	1.86E-09	3.07	0.00
0.001 gm / 0.59 mm	7	1.86E-10	0.31	0.00

Weight of pure Dessauite in grams (gm) and Calculated Diameter of a Sphere with a Density of 9.47 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

Dessauite Classification

Dana Class:

8.5.1.9 (8)Multiple Oxides with Nb, Ta, and Ti

(8.5)Dana Type

(8.5.1)Crichtonite group (ABC18 T2 O38)

8.5.1.1 Landauite NaMnZn2(Ti,Fe)6Ti12O38 R 3 3

8.5.1.2 Loveringite (Ca,Ce)(Ti,Fe,Cr,Mg)21O38 R 3 3

8.5.1.3 Crichtonite (Sr,La,Ce,Y)(Ti,Fe,Mn)21O38 R 3 3

8.5.1.4 Senaite Pb(Ti,Fe,Mn)21O38 R 3 3

8.5.1.5 Davidite-(La) (La,Ce,Ca)(Y,U)(Ti,Fe)20O38 R 3 3

8.5.1.6 Davidite-(Ce) (Ce,La)(Y,U)(Ti,Fe)20O38 R 3 3

8.5.1.7 Mathiasite (K,Ca,Sr)(Ti,Cr,Fe,Mg)21O38 R 3 3

8.5.1.8 Lindsleyite (Ba,Sr)(Ti,Cr,Fe,Mg)21O38 R 3 3

8.5.1.9 Dessauite ! (Sr,Pb)(Y,U)(Ti,Fe)20O38 P 3 3

8.5.1.10 Cleusonite! Pb(U,U)(Ti,Fe2,Fe3)20(O,OH)38 R 3 3

8.5.1.11 Gramaccioliite-(Y)! (Pb,Sr)(Y,Mn)Fe2(Ti,Fe)18O38 R 3 3

Strunz Class:

IV/C.09-45 IV - Oxides

IV/C - Oxides with metal : oxygen = 2:3 (M2O3 and related compounds)

IV/C.09 - Crichtonite group

IV/C.09-10 Landauite NaMnZn2(Ti,Fe)6Ti12O38 R 3 3

IV/C.09-20 Mathiasite (K,Ca,Sr)(Ti,Cr,Fe,Mg)21O38 R 3 3

IV/C.09-30 Loveringite (Ca,Ce)(Ti,Fe,Cr,Mg)21O38 R 3 3

IV/C.09-40 Crichtonite (Sr,La,Ce,Y)(Ti,Fe,Mn)21O38 R 3 3

IV/C.09-45 Dessauite (Sr,Pb)(Y,U)(Ti,Fe)20O38 P 3 3

IV/C.09-50 Lindsleyite (Ba,Sr)(Ti,Cr,Fe,Mg)21O38 R 3 3

IV/C.09-60 Davidite-(La) (La,Ce,Ca)(Y,U)(Ti,Fe)20O38 R 3 3

IV/C.09-62 Gramaccioliite-(Y)! (Pb,Sr)(Y,Mn)Fe2(Ti,Fe)18O38 R 3 3

IV/C.09-70 Davidite-(Ce) (Ce,La)(Y,U)(Ti,Fe)20O38 R 3 3

IV/C.09-80 Senaite Pb(Ti,Fe,Mn)21O38 R 3 3

Other Dessauite Information

References:

NAME( MinRec) PHYS. PROP.(Am.Min.,Vol.82,p807-811,1997) OPTIC PROP.(MinRec, v 29, p 235)

See Also:

Links to other databases for Dessauite :
1 -Am. Min. Crystal Structure Database 2 -Athena 3 -Google Images 4 -Google Scholar 5 -Handbook of Mineralogy (UofA) 6 -MinDAT 7 -MinMax(Deutsch) 8 -MinMax(English) 9 -Mineralienatlas (Deutsch) 10 -QUT Mineral Atlas 11 - Uranium Minerals 12 - WWW-MINCRYST

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Dessauite

(Sr,Pb)(Y,U)(Ti,Fe+++)20O38
Dana No: 8.5.1.9 Strunz No: IV/C.09-45
Locality:

Notes: