Crichtonite Mineral Data

General Crichtonite Information

Chemical Formula:

(Sr,La,Ce,Y)(Ti,Fe+++,Mn)21O38

Composition:

Molecular Weight = 1,772.61 gm

Strontium 3.46 % Sr 4.09 % SrO

Lanthanum 1.57 % La 1.84 % La₂O₃

Cerium 0.79 % Ce 0.93 % Ce₂O₃

Yttrium 0.50 % Y 0.64 % Y₂O₃

Titanium 38.09 % Ti 63.54 % TiO₂

Manganese 2.17 % Mn 3.12 % Mn₂O₃

Iron 17.96 % Fe 12.56 % FeO / 11.71 % Fe₂O₃

Lead 1.17 % Pb 1.26 % PbO

Oxygen 34.30 % O

______ ______

100.00 % 99.68 % = TOTAL OXIDE

Empirical Formula:

Sr_0.7La_0.2Ce_0.1Y_0.1Pb_0.1Ti_14.1Fe²⁺_3.1Fe³⁺_2.6Mn³⁺_0.7O₃₈

Environment:

In alpine-type fissure veins.

IMA Status:

Valid Species (Pre-IMA) 1813

Locality:

St. Christopher, Bourg d'Oisans, Isere, France. Link to MinDat.org Location Data.

Name Origin:

Named for Sir Alexander A. Crichton (1763-1856), Scottish physician and mineral collector.

Synonym:

ICSD 12122

PDF 22-1121

Crichtonite Image

Images:

Crichtonite

Comments: Black crichtonite crystal in quartz.
Location: Kriegalptal, Binntal, Wallis (Valais), Switzerland. Scale: Picture size 1.5 mm.
© Thomas Witzke / Abraxas-Verlag

Crichtonite Crystallography

Axial Ratios:

a:c = 1:2.00077

Cell Dimensions:

a = 10.374, c = 20.756, Z = 3; V = 1,934.49 Den(Calc)= 4.56

Crystal System:

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

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

By Intensity(I/I_o): 2.131(1), 2.875(1), 3.39(1),

Crystal Structure:

Mouse
drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
Keyboard
S - Stereo Pair on/off
H - Help Screen
I - Data Info
A - Atoms On/Off
P - Polyhedra On/Off
B - Bonds On/Off
Help on Above

Grey I E , Lloyd D J , White J S , American Mineralogist , 61 (1976) p.1203-1212, The structure of crichtonite and its relationship to senaite

Physical Properties of Crichtonite

Color:

Black.

Density:

4.46

Diaphaneity:

Opaque

Habit:

Rhombohedral Crystals - Occurs as well-formed crystals showing rhobohedral crystals.

Hardness:

5-6 - Between Apatite and Orthoclase

Luster:

Metallic - Dull

Streak:

dark gray

Optical Properties of Crichtonite

Optical Data:

NCalc= 2.52 - from Gladstone-Dale relationship (KC = 0.3323) where Ncalc=Dcalc*KC+1
NCalc= 2.48 - from Gladstone-Dale relationship (KC = 0.3323) where Ncalc=Dmeas*KC+1

Calculated Properties of Crichtonite

Electron Density:

Bulk Density (Electron Density)=4.30 gm/cc
note: Specific Gravity of Crichtonite =4.56 gm/cc.

Fermion Index:

Fermion Index = 0.05
Boson Index = 0.95

Photoelectric:

PE_Crichtonite= 47.08 barns/electron
U=PE_Crichtonite x r_electron= 202.44 barns/cc.

Radioactivity:

GRapi = 2,371.56 (Gamma Ray American Petroleum Institute Units)
Concentration of Crichtonite per GRapi unit = 421.66 (PPM)

**Estimated Radioactivity from Crichtonite** - mild
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 / 7.48 cm	52,812	1.43E-06	2,371.56	0.78
100 gm / 3.47 cm	5,281	1.43E-07	237.16	0.08
10 gm / 1.61 cm	528	1.43E-08	23.72	0.01
1 gm / 7.48 mm	53	1.43E-09	2.37	0.00
0.1 gm / 3.47 mm	5	1.43E-10	0.24	0.00
0.01 gm / 1.61 mm	1	1.43E-11	0.02	0.00
0.001 gm / 0.75 mm	0	1.43E-12	0.00	0.00

Weight of pure Crichtonite in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.56 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 ( 2.36 % REE)

Crichtonite Classification

Dana Class:

08.05.01.03 (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 Crichtonite Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Crichtonite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - MinDAT
10 - Mineralienatlas (Deutsch)
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info
14 - WWW-MINCRYST

Search for Crichtonite using:

[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Crichtonite :

A Bijoux Google Search for Crichtonite
Adam's Minerals Google Search for Crichtonite
Cape Minerals Google Search for Crichtonite
Dakota Matrix Minerals Google Search for Crichtonite
Excalibur Mineral Corp. Google Search for Crichtonite
Exceptional Minerals Google Search for Crichtonite
John Betts Fine Minerals Search for Crichtonite
McDougall Minerals Google Search for Crichtonite
Mineral News Website Link
Rock and Mineral Shows Google Search for Crichtonite
Weinrich Minerals, Inc. Google Search for Crichtonite

Ask about Crichtonite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

Print or Cut-and-Paste your Crichtonite Specimen Label here :

Crichtonite

(Sr,La,Ce,Y)(Ti,Fe+++,Mn)21O38
Dana No: 08.05.01.03 Strunz No: 04.CC.40
Locality:

Notes: