Holfertite Mineral Data

General Holfertite Information

Chemical Formula:

U++++++1.75TiCa0.25 O7.5(H2O)3

Composition:

Molecular Weight = 649.27 gm

Potassium 0.24 % K 0.29 % K₂O

Calcium 1.67 % Ca 2.33 % CaO

Uranium 63.79 % U 76.65 % UO₃

Titanium 7.15 % Ti 11.93 % TiO₂

Iron 0.34 % Fe 0.49 % Fe₂O₃

Hydrogen 0.93 % H 8.32 % H₂O

Oxygen 25.87 % O

______ ______

100.00 % 100.02 % = TOTAL OXIDE

Empirical Formula:

U_1.74Ti_0.97Ca_0.27Fe³⁺_0.04K_0.04O_7.5•3(H₂O)

Environment:

Found on hematite and topaz crystals in cavities and fractures in rhyolite.

IMA Status:

Approved IMA 2003 (Dana # Added)

Locality:

Starvation Canyon (Searles Canyon), Thomas Range, Juab Co., Utah, USA Link to MinDat.org Location Data.

Name Origin:

Named for John W. Holfert, claim holder at Starvation (formerly Searle) Canyon.

Synonym:

IMA2003-009

Holfertite Image

Images:

Holfertite

Comments: Yellow prismatic micro crystal of holfertite on clear topaz.
Location: Starvation Canyon, Topaz Valley, Juab Co., Utah, USA. Scale: Crystal size 0.5 mm.
© Tom Loomis / Dakota Matrix

Holfertite Crystallography

Axial Ratios:

a:c = 1:0.69743

Cell Dimensions:

a = 10.824, c = 7.549, Z = 3; V = 765.94 Den(Calc)= 4.22

Crystal System:

Trigonal - Pyramidal H-M Symbol (3) Space Group: P 3

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

By Intensity(I/I_o): 4.6(1), 2.9(0.8), 1.87(0.3),1.747(0.3), 1.211(0.3),

Physical Properties of Holfertite

Cleavage:

{110} Perfect

Color:

Canary yellow, Orange yellow.

Diaphaneity:

Translucent to transparent

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Acicular - Occurs as needle-like crystals.

Hardness:

4 - Fluorite

Luster:

Vitreous (Glassy)

Streak:

yellow

Optical Properties of Holfertite

Gladstone-Dale:

CI calc= -0.184 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2044,KC= 0.1727
Ncalc = 1.73

Optical Data:

Uniaxial (+), w=1.815, e=1.91, bire=0.0950.

Calculated Properties of Holfertite

Electron Density:

Bulk Density (Electron Density)=3.62 gm/cc
note: Specific Gravity of Holfertite =4.22 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Holfertite=1,687.98 barns/electron
U=PE_Holfertite x r_electron=6,113.57 barns/cc.

Radioactivity:

GRapi = 4,666,583.92 (Gamma Ray American Petroleum Institute Units)
Concentration of Holfertite per GRapi unit = 214.29 (PPB)

Holfertite 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) 6.52 ± 1.63 grams of pure Holfertite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 651.80 ±162.95 grams of pure Holfertite .

**Estimated Radioactivity from Holfertite** - very strong
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 / 7.68 cm	114,183,715	3.09E-03	4,666,583.92	1,534.22
100 gm / 3.56 cm	11,418,372	3.09E-04	466,658.39	153.42
10 gm / 1.65 cm	1,141,837	3.09E-05	46,665.84	15.34
1 gm / 7.68 mm	114,184	3.09E-06	4,666.58	1.53
0.1 gm / 3.56 mm	11,418	3.09E-07	466.66	0.15
0.01 gm / 1.65 mm	1,142	3.09E-08	46.67	0.02
0.001 gm / 0.77 mm	114	3.09E-09	4.67	0.00

Weight of pure Holfertite in grams (gm) and Calculated Diameter of a Sphere with a Density of 4.22 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

Holfertite Classification

Dana Class:

05.02.04.01 (05)Oxides Containing Uranium and Thorium

(05.02)with a cation charge of 6+ (AO3) and hydrated

(05.02.04)Dana Group

05.02.04.01 Holfertite! U1.75TiCa0.25O7.5(H2O)3 P 3 3

Strunz Class:

04.GB.70 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.G - Uranyl Hydroxides

04.GB -With additional cations (K, Ca, Ba, Pb, etc.); with mainly UO2(O,OH)5 pentagonal polyhedra

04.GB.70 Holfertite! U1.75TiCa0.25O7.5(H2O)3 P 3 3

Other Holfertite Information

References:

NAME( AmMin, v91, p1204) PHYS. PROP.(AmMin, v91, p1204) OPTIC PROP.(MinRec)

See Also:

Links to other databases for Holfertite :
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 Holfertite Specimen Label here :

Holfertite

U++++++1.75TiCa0.25 O7.5(H2O)3
Dana No: 05.02.04.01 Strunz No: 04.GB.70
Locality:

Notes:

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