Lucasite-(Ce) Mineral Data

General Lucasite-(Ce) Information

Chemical Formula:

CeTi2(O,OH)6

Composition:

Molecular Weight = 332.88 gm

Cerium 42.09 % Ce 49.30 % Ce₂O₃

Titanium 28.77 % Ti 47.99 % TiO₂

Hydrogen 0.30 % H 2.71 % H₂O

Oxygen 28.84 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

CeTi₂O₅(OH)

Environment:

In heavy-media concentrates form non-sandy tuff in an olivine lamproite diatreme.

IMA Status:

Approved IMA 1987

Locality:

Argyle AK1 diamondiferous diatreme mine, east Kimberley area, Western Australia. Link to MinDat.org Location Data.

Name Origin:

Named for Hans Lucas, CRA Exploration Pty., Ltd,. Who noted the mineral in concentrates.

Name Pronunciation:

Lucasite-(Ce)

Synonym:

ICSD 202362

PDF 40-1455

Lucasite-(Ce) Image

Images:

Lucasite-(Ce)

Comments: B&W image of a striated, euhedral lucasite-(Ce) crystal showing {001} and {101} faces. The dark substrate is calcite. (AmMin, v72:1006).
Location: Heavy-mineral concentrate derived from an olivine lamproite tuff at Argyle, in the east Kimberley region of Western Australia. Scale: See Image.
© American Mineralogist

Lucasite-(Ce) Crystallography

Axial Ratios:

a:b:c =0.5913:1:1.1155

Cell Dimensions:

a = 5.178, b = 8.756, c = 9.768, Z = 4; beta = 93.52° V = 442.03 Den(Calc)= 5.00

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: I2/a

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

By Intensity(I/I_o): 3.376(1), 3.203(0.8), 2.584(0.7),

Physical Properties of Lucasite-(Ce)

Cleavage:

{001} Good

Color:

Brown, Dark brown, Chocolate brown.

Diaphaneity:

Translucent

Fracture:

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

Habit:

Striated - Parallel lines on crystal surface or cleavage face.

Habit:

Subhedral Crystals - Occurs as crystals which tend to exhibit a recognizable crystal shape.

Hardness:

6-6.5 - Orthoclase-Pyrite

Luster:

Resinous

Streak:

white

Optical Properties of Lucasite-(Ce)

Gladstone-Dale:

CI calc= 0.017 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2642,KC= 0.2688
Ncalc = 2.34

Optical Data:

Biaxial (?), b=2.321

RL Anisotrophism:

Weak.

RL Color:

Gray with brown internal reflections.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Lucasite-(Ce) in Air**
λ	R	∑ R(λ)
470 nm	16.60
546 nm	15.60
589 nm	15.30
650 nm	15.00

**Calculated Relative Intensity Colors of Lucasite-(Ce) in Air**
Relative Intensity	0%	60%	100%	120%	180%	240%	300%	360%	420%	480%	540%	580%
R

Calculated Properties of Lucasite-(Ce)

Electron Density:

Bulk Density (Electron Density)=4.54 gm/cc
note: Specific Gravity of Lucasite-(Ce) =5.00 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_{Lucasite-(Ce)}= 219.25 barns/electron
U=PE_{Lucasite-(Ce)} x r_electron= 994.58 barns/cc.

Radioactivity:

GRapi = 40,733.02 (Gamma Ray American Petroleum Institute Units)
Concentration of Lucasite-(Ce) per GRapi unit = 24.55 (PPM)

Lucasite-(Ce) 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) 746.73 ±186.68 grams of pure Lucasite-(Ce) .

**Estimated Radioactivity from Lucasite-(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 / 7.26 cm	942,857	2.55E-05	40,733.02	13.39
100 gm / 3.37 cm	94,286	2.55E-06	4,073.30	1.34
10 gm / 1.56 cm	9,429	2.55E-07	407.33	0.13
1 gm / 7.26 mm	943	2.55E-08	40.73	0.01
0.1 gm / 3.37 mm	94	2.55E-09	4.07	0.00
0.01 gm / 1.56 mm	9	2.55E-10	0.41	0.00
0.001 gm / 0.73 mm	1	2.55E-11	0.04	0.00

Weight of pure Lucasite-(Ce) in grams (gm) and Calculated Diameter of a Sphere with a Density of 5.00 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 ( 2.10 % Th) From Sum REE Elements (42.09 % REE)

Lucasite-(Ce) Classification

Dana Class:

08.03.05.01 (08)Multiple Oxides with Nb, Ta, and Ti

(08.03)where A (B2O6)

(08.03.05)Dana Group

08.03.05.01 Lucasite-(Ce) CeTi2(O,OH)6 I2/a 2/m

Strunz Class:

04.DH.10 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.D - Metal:Oxygen = 1:2 and similar

04.DH -With large (ï¿½ medium-sized) cations; sheets of edge-sharing octahedra

04.DH.10 Kassite CaTi2O4(OH)2 P 2₁/a 2/m

04.DH.10 Lucasite-(Ce) CeTi2(O,OH)6 I2/a 2/m

Other Lucasite-(Ce) Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Am.Min.,Vol.72,p1006-1010,1987) OPTIC PROP.(Am.Min.,Vol.72, p1006-1010,1987)

See Also:

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

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Print or Cut-and-Paste your Lucasite-(Ce) Specimen Label here :

Lucasite-(Ce)

CeTi2(O,OH)6
Dana No: 08.03.05.01 Strunz No: 04.DH.10
Locality:

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