Kidwellite Mineral Data

General Kidwellite Information

Chemical Formula:

Na(Fe+++,Cu)9+x(PO4)6(OH)11•3(H2O)

Composition:

Molecular Weight = 1,368.34 gm

Sodium 1.68 % Na 2.26 % Na₂O

Iron 36.73 % Fe 52.52 % Fe₂O₃

Copper 2.32 % Cu 2.91 % CuO

Phosphorus 13.58 % P 31.12 % P₂O₅

Hydrogen 1.25 % H 11.19 % H₂O

Oxygen 44.43 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

NaFe³⁺₉Cu_0.5(PO₄)₆(OH)₁₁•3(H₂O)

Environment:

Assoicated with other phosphates in novaculite deposits.

IMA Status:

Approved IMA 1978

Locality:

Coon Creek mine, Shady, Polk County, Arkansas, USA. Link to MinDat.org Location Data.

Name Origin:

Named for Albert Laws Kidwell (1919-), Houston, Texas.

Name Pronunciation:

Kidwellite + Pronunciation

Kidwellite Image

Images:

Frondelite Kidwellite

Comments: Root beer colored crystals of frondelite and white kidwellite sticks on matrix.
Location: Sapucaia, Minas Gerais, Brazil. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Images:

Kidwellite

Comments: Yellowish green columnar aggregates of kidwellite crystals.
Location: Indian Mountain, Cherokee County, Alabama, USA. Scale: Not Given.
© Lou Perloff / Photo Atlas of Minerals

Images:

Strengite Kidwellite

Comments: Spherical, crystalline aggregate of purple strengite on green kidwellite.
Location: Three Oak Gap, Polk Co., Arkansas, USA. Scale: Crystal size 2 mm.
© Tom Loomis / Dakota Matrix

Kidwellite Crystallography

Axial Ratios:

a:b:c =3.8798:1:2.6958

Cell Dimensions:

a = 20.117, b = 5.185, c = 13.978, Z = 2; beta = 107.07° V = 1,393.77 Den(Calc)= 3.26

Crystal System:

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

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

By Intensity(I/I_o): 9.41(1), 3.413(0.55), 3.813(0.4),

Physical Properties of Kidwellite

Cleavage:

{100} Perfect

Color:

Greenish yellow, Greenish white, Yellow, Light green.

Density:

3.04

Diaphaneity:

Translucent

Habit:

Columnar - Forms columns

Habit:

Fibrous - Crystals made up of fibers.

Hardness:

3 - Calcite

Luster:

Silky

Streak:

yellow

Optical Properties of Kidwellite

Gladstone-Dale:

CI meas= 0.027 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.093 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2446,KPDmeas= 0.2623,KC= 0.2697
Ncalc = 1.82 - 1.88

Optical Data:

Biaxial (-), a=1.787, b=1.8, g=1.805, bire=0.0180

Pleochroism (x):

none.

Pleochroism (y):

none.

Pleochroism (z):

none.

Calculated Properties of Kidwellite

Electron Density:

Bulk Density (Electron Density)=2.98 gm/cc
note: Specific Gravity of Kidwellite =3.04 gm/cc.

Fermion Index:

Fermion Index = 0.0080023991
Boson Index = 0.9919976009

Photoelectric:

PE_Kidwellite= 12.63 barns/electron
U=PE_Kidwellite x rElectron Density= 37.61 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Kidwellite is Not Radioactive

Kidwellite Classification

Dana Class:

42.08.02.01 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen

(42.08)where (AB)7 (XO4)4 Zq ï¿½ x(H2O)

(42.08.02)Dana Group

42.08.02.01 Kidwellite Na(Fe,Cu)9x(PO4)6(OH)11•3(H2O) P 2/c 2/m

Strunz Class:

08.DK.20 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

08.DK -With large and medium-sized cations, (OH, etc.):RO4 > 1:1 and < 2:1

08.DK.20 Kidwellite Na(Fe,Cu)9x(PO4)6(OH)11•3(H2O) P 2/c 2/m

Other Kidwellite Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990, AmMin 89:1833) OPTIC PROP.(Dana8)

See Also:

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

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

Kidwellite

Na(Fe+++,Cu)9+x(PO4)6(OH)11•3(H2O)
Dana No: 42.08.02.01 Strunz No: 08.DK.20
Locality:

Notes:

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