Boltwoodite Mineral Data

[Newest Minerals] [Equipment] [Analytical Services] [About Us] [Mineral Gallery] [eBay Store]
See Also: [Diamond Crystals] [Mineral News] [Hudson Institute] [Minerals on CDROM]
Rare Minerals, Meteorites, Equipment and Analytical Services
Excalibur Mineral Company, World leaders in the supply of rare species
Serving the scientific and collector communities since 1974

General Boltwoodite Information

Chemical Formula:

HK(UO2)(SiO4)•1.5(H2O)

Composition:

Molecular Weight = 429.24 gm

Potassium 9.11 % K 10.97 % K₂O

Uranium 55.45 % U 62.91 % UO₂

Silicon 6.54 % Si 14.00 % SiO₂

Hydrogen 0.94 % H 8.39 % H₂O

Oxygen 27.96 % O

______ ______

100.00 % 96.27 % = TOTAL OXIDE

Empirical Formula:

HK(UO₂)(SiO₄)•1.5(H₂O)

Environment:

In the outer silicate zone of alteration surrounding hydrated uranyl oxides incrusting primary uraninite; also filling fractures at some distance from primary uraninite.

IMA Status:

Valid Species (Pre-IMA) 1956

Locality:

In the USA, from the Delta mine, Emery Co., Utah; the New Method mine, near Amboy, San Bernardino Co., California. Link to MinDat.org Location Data.

Name Origin:

For Bertram Borden Boltwood (1870-1927), radiochemist of Yale University, New Haven, Connecticut, USA, who devised the U-Pb method of measuring geologic time.

Name Pronunciation:

Boltwoodite + Pronunciation

Synonym:

ICSD 86631

Nenadkevite

PDF 35-490

Boltwoodite Image

Images:

Boltwoodite

Comments: Sprays of boltwoodite covering matrix.
Location: Rossing, Namibia. Scale: Size Not Given.
© John Veevaert

Images:

Boltwoodite

Comments: Bright yellow, prismatic crystals of boltwoodite.
Location: Rössing mine, Swakopmund District, Namibia. Scale: Picture size 2.5 mm.
© Paul M. Schumacher

Images:

Boltwoodite

Comments: Yellow, globular aggregates of boltwoodite on a ferruginous matrix.
Location: Repete Mine, San Juan County, Utah, USA. Scale: See Image.
© Jeff Weissman / Photographic Guide to Mineral Species

Boltwoodite Crystallography

Axial Ratios:

a:b:c =1.9201:1:1.7296

Cell Dimensions:

a = 13.71, b = 7.14, c = 12.35, Z = 6; beta = 102.2° V = 1,181.63 Den(Calc)= 3.62

Crystal System:

Monoclinic - SphenoidalH-M Symbol (2) Space Group: P 2₁

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

By Intensity(I/I_o): 6.81(1), 3.4(0.9), 2.95(0.8),

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

Stohl F V , Smith D K , American Mineralogist , 66 (1981) p.610-625, The crystal chemistry of the uranyl silicate minerals

View Additional jPOWD Structure files for Boltwoodite
[1]

Physical Properties of Boltwoodite

Cleavage:

{010} Perfect, {001} Distinct

Color:

Yellow, Light yellow.

Density:

3.6

Hardness:

3.5-4 - Copper Penny-Fluorite

Luminescence:

Fluorescent, Short UV=dull green, Long UV=dull green.

Luster:

Vitreous - Pearly

Streak:

white

Optical Properties of Boltwoodite

Gladstone-Dale:

CI meas= -0.346 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.338 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1901,KPDmeas= 0.1912,KC= 0.1421
Ncalc = 1.51

Optical Data:

Biaxial (-), a=1.669, b=1.6955, g=1.7005, bire=0.0315

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.

Calculated Properties of Boltwoodite

Electron Density:

Bulk Density (Electron Density)=3.19 gm/cc
note: Specific Gravity of Boltwoodite =3.62 gm/cc.

Fermion Index:

Fermion Index = 0.0071947992
Boson Index = 0.9928052008

Photoelectric:

PE_Boltwoodite=1,429.97 barns/electron
U=PE_Boltwoodite x r_electron=4,558.55 barns/cc.

Radioactivity:

GRapi = 4,162,622.33 (Gamma Ray American Petroleum Institute Units)
Concentration of Boltwoodite per GRapi unit = 240.23 (PPB)

Boltwoodite 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) 7.31 ± 1.83 grams of pure Boltwoodite .
Estimated Maximum U.S. Postal Shipping Size (10 mRem/hr limit, Unshielded 100 cm box) 730.71 ±182.68 grams of pure Boltwoodite .

**Estimated Radioactivity from Boltwoodite** - 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 / 8.08 cm	99,264,658	2.68E-03	4,162,622.33	1,368.53
100 gm / 3.75 cm	9,926,466	2.68E-04	416,262.23	136.85
10 gm / 1.74 cm	992,647	2.68E-05	41,626.22	13.69
1 gm / 8.08 mm	99,265	2.68E-06	4,162.62	1.37
0.1 gm / 3.75 mm	9,926	2.68E-07	416.26	0.14
0.01 gm / 1.74 mm	993	2.68E-08	41.63	0.01
0.001 gm / 0.81 mm	99	2.68E-09	4.16	0.00

Weight of pure Boltwoodite in grams (gm) and Calculated Diameter of a Sphere with a Density of 3.62 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

Boltwoodite Classification

Dana Class:

53.03.01.05 (53)Nesosilicate Insular SiO4 Groups and Other Anions of Complex Cations

(53.03)with (UO2)

(53.03.01)Uranophane group

53.03.01.01 Kasolite Pb(UO2)SiO4•(H2O) P 2₁/a 2/m

53.03.01.02 Uranophane Ca(UO2)2SiO3(OH)2•5(H2O) P 2₁ 2

53.03.01.03 Sklodowskite (H3O)2Mg(UO2)2(SiO4)2•4(H2O) C 2/m 2/m

53.03.01.04 Cuprosklodowskite Cu[(UO2)(SiO2OH)]2•6(H2O) P1 1

53.03.01.05 Boltwoodite HK(UO2)(SiO4)•1.5(H2O) P 2₁ 2

53.03.01.06 Natroboltwoodite (H3O)(Na,K)(UO2)SiO4•(H2O) P 2₁2₁2₁ 2 2 2

53.03.01.07 Oursinite (Co,Mg)(H3O)2[(UO2)SiO4]2•3(H2O) Aba2,Abam Ortho

53.03.01.08 Swamboite UH6(UO2)6(SiO4)6•30(H2O) P 2₁/a 2/m

53.03.01.09 Uranophane-beta Ca[(UO2)SiO3(OH)]2•(H2O) P 2₁/a 2/m

Strunz Class:

09.AK.15 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AK -Uranyl neso- and polysilicates

09.AK.15 Boltwoodite HK(UO2)(SiO4)•1.5(H2O) P 2₁ 2

09.AK.15 Kasolite Pb(UO2)SiO4•(H2O) P 2₁/a 2/m

09.AK.15 Uranophane Ca(UO2)2SiO3(OH)2•5(H2O) P 2₁ 2

09.AK.15 Natroboltwoodite (H3O)(Na,K)(UO2)SiO4•(H2O) P 2₁2₁2₁ 2 2 2

Other Boltwoodite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Boltwoodite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - Ecole des Mines de Paris
6 - Google Images
7 - Google Scholar
8 - Handbook of Mineralogy (MinSocAm)
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - MinMax(Deutsch)
12 - MinMax(English)
13 - Mineralienatlas (Deutsch)
14 - Philatelic Mineralogy
15 - QUT Mineral Atlas
16 - Ruff.Info
17 - Scandinavian mineral gallery
18 - Uranium Minerals
19 - WWW-MINCRYST

Search for Boltwoodite using:

[ALTAVISTA] [AOL] [All-The-Web] [HotBot] [Ixquick] [MAMMA] [MSN.COM] [Netscape] [Scirus] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Boltwoodite :

AA Mineral Specimens

B & L Fine Minerals

Crystalarium.com

Dan Weinrich Fine Minerals

Dan Weinrich Auctions

Dakota Matrix

Desert Winds Gems and Minerals

John Betts Fine Minerals

Mason's Minerals

Mineral News

Mineral of the Month Club

Wrights Rock Shop

Translate Boltwoodite Mineral Data :

Ask about Boltwoodite 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 Boltwoodite Specimen Label here :

Boltwoodite

HK(UO2)(SiO4)•1.5(H2O)
Dana No: 53.03.01.05 Strunz No: 09.AK.15
Locality:

Notes: