Dessauite Mineral Data (original) (raw)
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:
Sr0.75Pb0.25Y0.7U0.3Ti15Fe3+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.
Name Pronunciation:
Dessauite + Pronunciation 
Synonym:
ICSD 77505
IMA1994-057
Romanite
Dessauite Image
Images:
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Dessauite Comments: SEM photograph of tabular {001} dessauite crystals on calcite. (AmMin v82:807). Location: Buca della Vena mine, Tuscany, Italy.Scale: Scale bar: 0 .1mm. © American Mineralogist |
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Dessauite Crystallography
Axial Ratios:
a:c = 1:2.01454
Cell Dimensions:
a = 10.385, c = 20.921, Z = 3; V = 1,954.01 Den(Calc)= 4.73
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
Diaphaneity:
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= 2.62 - 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 | R 2 |  |
∑ 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 | R 2 | |
∑ 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
| RelativeIntensity | 0% | 60% | 100% | 120% | 180% | 240% | 300% | 360% | 420% | 480% | 540% | 550% |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| R1 | ||||||||||||
| R2 |
Calculated Relative Intensity Colors of Dessauite in Oil
| RelativeIntensity | 0% | 100% | 200% | 300% | 400% | 500% | 600% | 700% | 800% | 900% | 1000% |
|---|---|---|---|---|---|---|---|---|---|---|---|
| R1 | |||||||||||
| R2 |
Calculated Properties of Dessauite
Electron Density:
Bulk Density (Electron Density)=4.42 gm/cc
note: Specific Gravity of Dessauite =4.73 gm/cc.
Fermion Index:
Fermion Index = 0.06
Boson Index = 0.94
Photoelectric:
PEDessauite = 158.61 barns/electron
U=PEDessauite x relectron= 701.41 barns/cc.
Radioactivity:
GRapi = 306,522.05 (Gamma Ray American Petroleum Institute Units)
Concentration of Dessauite per GRapi unit = 3.26 (PPM)
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
| SpecimenSizeWeight/Volume(Sphere) * | CalculatedActivityBecquerels(Bq) | CalculatedActivityCuries (Ci) | EstimatedActivityGR(api) | EstimatedExposure(mRem**)/hrIf Held in HandFor One Hour |
|---|---|---|---|---|
| 1000 gm / 7.39 cm | 6,884,821 | 1.86E-04 | 306,522.05 | 100.77 |
| 100 gm / 3.43 cm | 688,482 | 1.86E-05 | 30,652.21 | 10.08 |
| 10 gm / 1.59 cm | 68,848 | 1.86E-06 | 3,065.22 | 1.01 |
| 1 gm / 7.39 mm | 6,885 | 1.86E-07 | 306.52 | 0.10 |
| 0.1 gm / 3.43 mm | 688 | 1.86E-08 | 30.65 | 0.01 |
| 0.01 gm / 1.59 mm | 69 | 1.86E-09 | 3.07 | 0.00 |
| 0.001 gm / 0.74 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 4.73 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:
08.05.01.09 (08)Multiple Oxides with Nb, Ta, and Ti
(08.05)Dana Type
(08.05.01)Crichtonite group (ABC18 T2 O38)
08.05.01.01 Landauite NaMnZn2(Ti,Fe)6Ti12O38 R 3 3
08.05.01.02 Loveringite (Ca,Ce)(Ti,Fe,Cr,Mg)21O38 R 3 3
08.05.01.03 Crichtonite (Sr,La,Ce,Y)(Ti,Fe,Mn)21O38 R 3 3
08.05.01.04 Senaite Pb(Ti,Fe,Mn)21O38 R 3 3
08.05.01.05 Davidite-(La) (La,Ce,Ca)(Y,U)(Ti,Fe)20O38 R 3 3
08.05.01.06 Davidite-(Ce) (Ce,La)(Y,U)(Ti,Fe)20O38 R 3 3
08.05.01.07 Mathiasite (K,Ca,Sr)(Ti,Cr,Fe,Mg)21O38 R 3 3
08.05.01.08 Lindsleyite (Ba,Sr)(Ti,Cr,Fe,Mg)21O38 R 3 3
08.05.01.09 Dessauite! (Sr,Pb)(Y,U)(Ti,Fe)20O38 P 3 3
08.05.01.10 Cleusonite! Pb(U,U)(Ti,Fe,Fe)20(O,OH)38 R 3 3
08.05.01.11 Gramaccioliite-(Y)! (Pb,Sr)(Y,Mn)Fe2(Ti,Fe)18O38 R 3 3
Strunz Class:
04.CC.40 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate
04.C - Metal:Oxygen = 2:3, 3:5, and Similar
04.CC -With large and medium-sized cations
04.CC.40 Crichtonite (Sr,La,Ce,Y)(Ti,Fe,Mn)21O38 R 3 3
04.CC.40 Dessauite! (Sr,Pb)(Y,U)(Ti,Fe)20O38 P 3 3
04.CC.40 Davidite-(Ce) (Ce,La)(Y,U)(Ti,Fe)20O38 R 3 3
04.CC.40 Davidite-(La) (La,Ce,Ca)(Y,U)(Ti,Fe)20O38 R 3 3
04.CC.40 Mathiasite (K,Ca,Sr)(Ti,Cr,Fe,Mg)21O38 R 3 3
04.CC.40 Lindsleyite (Ba,Sr)(Ti,Cr,Fe,Mg)21O38 R 3 3
04.CC.40 Landauite NaMnZn2(Ti,Fe)6Ti12O38 R 3 3
04.CC.40 Loveringite (Ca,Ce)(Ti,Fe,Cr,Mg)21O38 R 3 3
04.CC.40 Senaite Pb(Ti,Fe,Mn)21O38 R 3 3
04.CC.40 Cleusonite! Pb(U,U)(Ti,Fe,Fe)20(O,OH)38 R 3 3
04.CC.40 Gramaccioliite-(Y)! (Pb,Sr)(Y,Mn)Fe2(Ti,Fe)18O38 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 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - Handbook of Mineralogy (UofA)
7 - MinDAT
8 - Mineralienatlas (Deutsch)
9 - Online Mineral Museum
10 - QUT Mineral Atlas
11 - Ruff.Info
12 - Uranium Minerals
13 - WWW-MINCRYST
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Print or Cut-and-Paste your Dessauite Specimen Label here :
Dessauite
(Sr,Pb)(Y,U)(Ti,Fe+++)20O38
Dana No: 08.05.01.09 Strunz No: 04.CC.40
Locality:
Notes: