Dissakisite-(La) Mineral Data

General Dissakisite-(La) Information

Chemical Formula:

(Ca,Fe++,Th, La)(La,REE,Ca)(Al,Cr,Ti)2(Mg,Fe,Al)Si3O12(OH,F) with La > Ce

Composition:

Molecular Weight = 551.33 gm

Sodium 0.01 % Na 0.01 % Na₂O

Strontium 0.16 % Sr 0.19 % SrO

Calcium 8.69 % Ca 12.15 % CaO

Lanthanum 7.94 % La 9.31 % La₂O₃

Cerium 6.66 % Ce 7.80 % Ce₂O₃

Praeseodymium 0.49 % Pr 0.57 % Pr₂O₃

Samarium 0.05 % Sm 0.06 % Sm₂O₃

Gadolinium 0.03 % Gd 0.03 % Gd₂O₃

Erbium 0.03 % Er 0.03 % Er₂O₃

Thorium 3.79 % Th 4.31 % ThO₂

Magnesium 2.74 % Mg 4.55 % MgO

Scandium 0.02 % Sc 0.03 % Sc₂O₃

Uranium 0.13 % U 0.15 % UO₂

Titanium 0.26 % Ti 0.43 % TiO₂

Manganese 0.09 % Mn 0.12 % MnO

Aluminum 9.00 % Al 17.00 % Al₂O₃

Vanadium 0.07 % V 0.12 % VO₂

Zinc 0.18 % Zn 0.22 % ZnO

Chromium 1.40 % Cr 1.83 % CrO

Gallium 0.01 % Ga 0.02 % Ga₂O₃

Iron 4.08 % Fe 3.13 % FeO / 2.17 % Fe₂O₃

Silicon 15.13 % Si 32.37 % SiO₂

Nickel 0.11 % Ni 0.14 % NiO

Phosphorus 0.04 % P 0.10 % P₂O₅

Hydrogen 0.18 % H 1.63 % H₂O

Neodymium 0.99 % Nd 1.16 % Nd₂O₃

Oxygen 37.70 % O

Fluorine 0.03 % F 0.03 % F

- % F -0.01 % -O=F₂

______ ______

100.00 % 99.73 % = TOTAL OXIDE

Empirical Formula:

Ca_1.19Mn²⁺_0.009Sr_0.01Na_0.002Th_0.09U_0.003La_0.31Ce_0.26Pr_0.01Nd_0.03Sm_0.002Gd_0.001Er_0.001Al_1.81 Mg_0.62Fe²⁺_0.24Fe³⁺_0.15Cr_0.14(OH)

Environment:

Occurs in peridotite incorporated in a Variscan subducted crustal slab which crystallised under eclogite-facies conditions or during the early stage of retrogression in the amphibol ite facies. Mg-analogue of allanite-(L

IMA Status:

Approved IMA 2003 (Dana # Added)

Locality:

Found in a peridotite body from the Ulten zone (Austroalpine domain, Eastern Alps. Link to MinDat.org Location Data.

Name Origin:

Named for its A2 site cation content and relationship to Dissakisite-(Ce).

Synonym:

IMA2003-007

Dissakisite-(La) Image

Images:

Dissakisite-(La)

Comments: B&W macrophotograph of dissakisite-(La) from the as matrix constituents and Cr-rich spinel in a peridotite matrix. AmMin, v90 p 1178.
Location: Ulten zone, Eastern Alps, Italy. Scale: See Image.
© American Mineralogist

Images:

Dissakisite-(La)

Comments: B&W thin section image showing radial cracks from dissakisite-(La) (dik) propagating into the surrounding olivine (ol). AmMin, v90 p 1178.
Location: Ulten zone, Eastern Alps, Italy. Scale: See image.
© American Mineralogist

Dissakisite-(La) Crystallography

Axial Ratios:

a:b:c =1.5655:1:1.7879

Cell Dimensions:

a = 8.959, b = 5.7226, c = 10.232, Z = 2; beta = 115.19° V = 474.70 Den(Calc)= 3.86

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 2₁/m

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

By Intensity(I/I_o): 2.926(1)(113 ), 2.86(0.53)(020 ), 2.553(0.51)(202 ),3.526(0.49)(211 ), 2.699(0.44)(120 ),

Physical Properties of Dissakisite-(La)

Cleavage:

{001} Imperfect

Color:

Black, Very dark brown.

Density:

3.79

Diaphaneity:

Translucent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Habit:

Anhedral Grains - Granular minerals without the expression of crystal shapes

Habit:

Inclusions - Generally found as inclusions in other minerals.

Hardness:

6.5-7 - Pyrite-Quartz

Luster:

Vitreous (Glassy)

Streak:

pale greenish gray

Optical Properties of Dissakisite-(La)

Gladstone-Dale:

CI meas= 0.006 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.024 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1928,KPDmeas= 0.1963,KC= 0.1976
Ncalc = 1.75 - 1.76

Optical Data:

Biaxial (+), a=1.7395, b=1.7434, g=1.7495, bire=0.0100, 2V(Calc)=78, 2V(Meas)=77. Dispersion r < v medium.

Calculated Properties of Dissakisite-(La)

Electron Density:

Bulk Density (Electron Density)=3.62 gm/cc
note: Specific Gravity of Dissakisite-(La) =3.79 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_{Dissakisite-(La)}= 167.08 barns/electron
U=PE_{Dissakisite-(La)} x r_electron= 605.18 barns/cc.

Radioactivity:

GRapi = 87,782.70 (Gamma Ray American Petroleum Institute Units)
Concentration of Dissakisite-(La) per GRapi unit = 11.39 (PPM)

Dissakisite-(La) 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) 346.50 ± 86.62 grams of pure Dissakisite-(La) .

**Estimated Radioactivity from Dissakisite-(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 / 7.96 cm	1,928,865	5.21E-05	87,782.70	28.86
100 gm / 3.69 cm	192,887	5.21E-06	8,778.27	2.89
10 gm / 1.71 cm	19,289	5.21E-07	877.83	0.29
1 gm / 7.96 mm	1,929	5.21E-08	87.78	0.03
0.1 gm / 3.69 mm	193	5.21E-09	8.78	0.00
0.01 gm / 1.71 mm	19	5.21E-10	0.88	0.00
0.001 gm / 0.80 mm	2	5.21E-11	0.09	0.00

Weight of pure Dissakisite-(La) in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.79 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

Dissakisite-(La) Classification

Dana Class:

58.02.01c.05 (58)Sorosilicate Insular, Mixed, Single, and Larger Tetrahedral Groups

(58.02)with cations in [6] and higher coordination; single and double groups (n=1,2)

(58.02.01c)Epidote group (Allanite subgroup)

58.02.01c.01 Allanite-(Ce) (Ce,Ca,Y)2(Al,Fe)3(SiO4)3(OH) P 2₁/m 2/m

58.02.01c.02 Allanite-(La)! Ca(REE,Ca)Al2(Fe,Fe)(SiO4)(Si2O7)O(OH) P 2₁/m 2/m

58.02.01c.03 Allanite-(Y) (Y,Ce,Ca)2(Al,Fe)3(SiO4)3(OH) P 2₁/m 2/m

58.02.01c.04 Dissakisite-(Ce) Ca(Ce,REE)(Mg,Fe)(Al,Fe)2Si3O12(OH) P 2₁/m 2/m

58.02.01c.05 Dissakisite-(La)! (Ca,Fe,Th,La)(La,REE,Ca)(Al,Cr,Ti)2(Mg,Fe,Al)Si3O12(OH,F)withLa>Ce P 2₁/m 2/m

58.02.01c.06 Manganiandrosite-(La)! (Mn,Ca)(La,Ce,Ca,Nd)AlMnMn(SiO4)(Si2O7)O(OH) P 2₁/m 2/m

58.02.01c.07 Ferriallanite-(Ce)! CaCe(Fe,Fe,Al)3[SiO4][Si2O7]O(OH) P 2₁/m 2/m

58.02.01c.08 Vastmanlandite-(Ce)! (Ce,La)3CaAl2Mg2[Si2O7][SiO4]3F(OH)2 P 2₁/m 2/m

58.02.01c.09 Manganiandrosite-(Ce)! (Mn,Ca)(Ce,REE)AlMnMn(Si2O7)(SiO4)O(OH) P 2₁/m 2/m

58.02.01c.10 Vanadoandrosite-(Ce)! (Mn,Ca)(REE)VAlMn(Si2O7)(SiO4)O(OH) P 2₁/m 2/m

Strunz Class:

09.BG.05b 09 - SILICATES (Germanates)

09.B - Sorosilicates

09.BG -Sorosilicates with mixed SiO4 and Si2O7 groups;

09.BG.05b Allanite-(La)! Ca(REE,Ca)Al2(Fe,Fe)(SiO4)(Si2O7)O(OH) P 2₁/m 2/m

09.BG.05b Allanite-(Y) (Y,Ce,Ca)2(Al,Fe)3(SiO4)3(OH) P 2₁/m 2/m

09.BG.05b Allanite-(Ce) (Ce,Ca,Y)2(Al,Fe)3(SiO4)3(OH) P 2₁/m 2/m

09.BG.05b Manganiandrosite-(La)! (Mn,Ca)(La,Ce,Ca,Nd)AlMnMn(SiO4)(Si2O7)O(OH) P 2₁/m 2/m

09.BG.05b Dissakisite-(Ce) Ca(Ce,REE)(Mg,Fe)(Al,Fe)2Si3O12(OH) P 2₁/m 2/m

09.BG.05b Manganiandrosite-(Ce)! (Mn,Ca)(Ce,REE)AlMnMn(Si2O7)(SiO4)O(OH) P 2₁/m 2/m

09.BG.05b Vanadoandrosite-(Ce)! (Mn,Ca)(REE)VAlMn(Si2O7)(SiO4)O(OH) P 2₁/m 2/m

09.BG.05b Dissakisite-(La)! (Ca,Fe,Th,La)(La,REE,Ca)(Al,Cr,Ti)2(Mg,Fe,Al)Si3O12(OH,F)withLa>Ce P 2₁/m 2/m

09.BG.05b Ferriallanite-(Ce)! CaCe(Fe,Fe,Al)3[SiO4][Si2O7]O(OH) P 2₁/m 2/m

09.BG.05b Uedaite-(Ce)! MnCeAl2Fe(Si2O7)(SiO4)O(OH) P 2₁/m 2/m

Other Dissakisite-(La) Information

References:

NAME( AmMin, v90, p 1177) PHYS. PROP.(AmMin, v90, p 1177, v91, p104) OPTIC PROP.(AmMin, v90, p 1177)

See Also:

Links to other databases for Dissakisite-(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 Dissakisite-(La) Specimen Label here :

Dissakisite-(La)

(Ca,Fe++,Th, La)(La,REE,Ca)(Al,Cr,Ti)2(Mg,Fe,Al)Si3O12(OH,F) with La > Ce
Dana No: 58.02.01c.05 Strunz No: 09.BG.05b
Locality:

Notes: