Khristovite-(Ce) Mineral Data

General Khristovite-(Ce) Information

Chemical Formula:

(Ca,REE)(Ce,REE)(Mg,Fe,Cr,Ti,V,Al)Mn++Al(SiO4)(Si2O7)(OH)(F,O)

Composition:

Molecular Weight = 610.88 gm

Calcium 5.25 % Ca 7.34 % CaO

Cerium 11.47 % Ce 13.43 % Ce₂O₃

La,Ce,Pr,Nd,Sm, 16.50 % RE 19.25 % REE₂O₃

Magnesium 1.59 % Mg 2.64 % MgO

Titanium 0.78 % Ti 1.31 % TiO₂

Manganese 8.99 % Mn 11.61 % MnO

Aluminum 4.86 % Al 9.18 % Al₂O₃

Vanadium 0.42 % V 0.61 % V₂O₃

Chromium 0.85 % Cr 1.24 % Cr₂O₃

Iron 0.91 % Fe 1.18 % FeO

Silicon 13.79 % Si 29.51 % SiO₂

Hydrogen 0.16 % H 1.47 % H₂O

Oxygen 32.08 % O

Fluorine 2.33 % F 2.33 % F

- % F -0.98 % -O=F₂

______ ______

100.00 % 100.13 % = TOTAL OXIDE

Empirical Formula:

Ca_0.8REE_0.2Ce_0.5REE_0.5Mg_0.4Fe²⁺_0.1Cr_0.1Ti_0.1V³⁺_0.05Mn²⁺Al_1.1(SiO₄)(Si₂O₇)(OH)F_0.75O_0.25

Environment:

Occurs in rhodonite in garnet-biotite-quartz-rich exo-contact of the subalkaline granites of the Inyl'chek massif.

IMA Status:

Approved IMA 1991 - Dana Number Modified from 58.2.1a.9

Locality:

On the northern slope of the Inyl'chek Range, southwestern Tien-shan, Kirgiziya, Russia. Link to MinDat.org Location Data.

Name Origin:

Named for Evgenia Valdimirovicha Khristova (1933-), Russian geologist and specialist in Tien-shan geology.

Name Pronunciation:

Khristovite-(Ce) + Pronunciation

Synonym:

IMA1991-055

Khristovite-(Ce) Image

Images:

Khristovite-(Ce)

Comments: Three tabular crystals of reddish-brown khristovite-(Ce) in pink rhodonite matrix. Associated mineral is yellowish-brown Fe-free hejtmanite (inylchekite var.).
Location: Rhodonite occurrence, Muzeinyi Valley, Inyl'chek Range, Issyk-Kul'skaya Oblast, Kyrgyzstan. Scale: Picture Size 3x1.7 mm.
© Pavel M. Kartashov

Khristovite-(Ce) Crystallography

Axial Ratios:

a:b:c =1.5488:1:1.7583

Cell Dimensions:

a = 8.903, b = 5.748, c = 10.107, Z = 2; beta = 113.41° V = 474.65 Den(Calc)= 4.27

Crystal System:

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

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

By Intensity(I/I_o): 2.91(1), 2.63(0.8), 2.73(0.7),

Physical Properties of Khristovite-(Ce)

Cleavage:

{001} Good

Color:

Brown, Dark brown.

Density:

4.05 - 4.11, Average = 4.08

Diaphaneity:

Transparent

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Hardness:

5 - Apatite

Luster:

Vitreous (Glassy)

Streak:

brownish

Optical Properties of Khristovite-(Ce)

Gladstone-Dale:

CI meas= -0.033 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.013 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1847,KPDmeas= 0.1933,KC= 0.1872
Ncalc = 1.76 - 1.8

Optical Data:

Biaxial (-), a=1.773, b=1.79, g=1.803, bire=0.0300, 2V(Calc)=80, 2V(Meas)=83. Dispersion r < v medium.

Calculated Properties of Khristovite-(Ce)

Electron Density:

Bulk Density (Electron Density)=4.02 gm/cc
note: Specific Gravity of Khristovite-(Ce) =4.27 gm/cc.

Fermion Index:

Fermion Index = 0.04
Boson Index = 0.96

Photoelectric:

PE_{Khristovite-(Ce)}= 159.83 barns/electron
U=PE_{Khristovite-(Ce)} x r_electron= 643.26 barns/cc.

Radioactivity:

GRapi = 28,179.57 (Gamma Ray American Petroleum Institute Units)
Concentration of Khristovite-(Ce) per GRapi unit = 35.49 (PPM)

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

**Estimated Radioactivity from Khristovite-(Ce)** - weak
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 / 7.65 cm	627,829	1.70E-05	28,179.57	9.26
100 gm / 3.55 cm	62,783	1.70E-06	2,817.96	0.93
10 gm / 1.65 cm	6,278	1.70E-07	281.80	0.09
1 gm / 7.65 mm	628	1.70E-08	28.18	0.01
0.1 gm / 3.55 mm	63	1.70E-09	2.82	0.00
0.01 gm / 1.65 mm	6	1.70E-10	0.28	0.00
0.001 gm / 0.76 mm	1	1.70E-11	0.03	0.00

Weight of pure Khristovite-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.27 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 ( 1.40 % Th) From Sum REE Elements (27.97 % REE)

Khristovite-(Ce) Classification

Dana Class:

58.02.01d.02 (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)

(58.02.01d)Epidote group (Dollaseite subgroup)

58.02.01d.01 Dollaseite-(Ce) CaCeMg2AlSi3O11(OH,F)2 P 2₁/m 2/m

58.02.01d.02 Khristovite-(Ce) (Ca,REE)(Ce,REE)(Mg,Fe,Cr,Ti,V,Al)MnAl(SiO4)(Si2O7)(OH)(F,O) P 2₁/m 2/m

Strunz Class:

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

09.B - Sorosilicates

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

09.BG.05c Dollaseite-(Ce) CaCeMg2AlSi3O11(OH,F)2 P 2₁/m 2/m

09.BG.05c Khristovite-(Ce) (Ca,REE)(Ce,REE)(Mg,Fe,Cr,Ti,V,Al)MnAl(SiO4)(Si2O7)(OH)(F,O) P 2₁/m 2/m

Other Khristovite-(Ce) Information

References:

NAME( Dana8) PHYS. PROP.(37th List of New Min.,Min. Mag.,1996) OPTIC PROP.(Dana8)

See Also:

Links to other databases for Khristovite-(Ce) :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - GeoScienceWorld
5 - Google Images
6 - Google Scholar
7 - MinDAT
8 - Mineralienatlas (Deutsch)
9 - Online Mineral Museum
10 - QUT Mineral Atlas
11 - Ruff.Info

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Khristovite-(Ce)

(Ca,REE)(Ce,REE)(Mg,Fe,Cr,Ti,V,Al)Mn++Al(SiO4)(Si2O7)(OH)(F,O)
Dana No: 58.02.01d.02 Strunz No: 09.BG.05c
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