Zimbabweite Mineral Data

General Zimbabweite Information

Chemical Formula:

Na(Pb,Na,K)2(Ta,Nb,Ti)4As+++4O18

Composition:

Molecular Weight = 1,498.05 gm

Potassium 1.30 % K 1.57 % K₂O

Sodium 2.30 % Na 3.10 % Na₂O

Tantalum 38.65 % Ta 47.20 % Ta₂O₅

Titanium 0.96 % Ti 1.60 % TiO₂

Niobium 3.72 % Nb 5.32 % Nb₂O₅

Arsenic 20.01 % As 26.41 % As₂O₃

Lead 13.83 % Pb 14.37 % Pb₂O

Oxygen 19.22 % O

______ ______

100.00 % 99.57 % = TOTAL OXIDE

Empirical Formula:

Na_1.5K_0.5PbAs₄Ta_3.2Nb_0.6Ti_0.3O₁₈

Environment:

In a kaolinized pegmatite.

IMA Status:

Approved IMA 1986

Locality:

St. Ann's mine, Karoi district, SE of Miami, Zimbabwe. Link to MinDat.org Location Data.

Name Origin:

Named for the country of origin.

Name Pronunciation:

Zimbabweite + Pronunciation

Synonym:

ICSD 202709

PDF 39-356

Search for Zimbabweite Images

Images:

Image not yet available on Webmineral.com

Try searching images.google.com or Mindat Picture Gallary for mineral pictures. Caution: The images retrieved may not be appropriate.

Zimbabweite Crystallography

Axial Ratios:

a:b:c =0.801:1:0.568

Cell Dimensions:

a = 12.245, b = 15.287, c = 8.684, Z = 4; V = 1,625.55 Den(Calc)= 6.12

Crystal System:

Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: Ccmb

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

By Intensity(I/I_o): 3.195(1), 2.882(0.7), 2.99(0.7),

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

Duesler E N , Chakoumakos B C , Foord E E , American Mineralogist , 73 (1988) p.1186-1190, Zimbabweite, Na(Pb,Na,K)2As4(Ta,Nb,Ti)4O18, an arsenite-tantalate with a, novel corner-linked octahedral sheet

Physical Properties of Zimbabweite

Cleavage:

{010} Perfect

Color:

Yellow brown, Honey yellow.

Density:

6.2

Diaphaneity:

Translucent

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Euhedral Crystals - Occurs as well-formed crystals showing good external form.

Habit:

Tabular - Form dimensions are thin in one direction.

Hardness:

5-5.5 - Apatite-Knife Blade

Luminescence:

Non-fluorescent.

Luster:

Adamantine

Magnetism:

Nonmagnetic

Streak:

white

Optical Properties of Zimbabweite

Gladstone-Dale:

CI meas= -0.089 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.104 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1797,KPDmeas= 0.1774,KC= 0.1629
Ncalc = 2 - 2.01

Optical Data:

Biaxial (+), a=2.1, 2V(Meas)=80. Dispersion r < v very strong.

Pleochroism (x):

pale yellow brown.

Pleochroism (y):

light reddish brown.

Pleochroism (z):

reddish brown.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Zimbabweite in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
470 nm	17.60	17.80
546 nm	17.00	17.10
589 nm	16.60	16.70
650 nm	16.20	16.50

**Calculated Relative Intensity Colors of Zimbabweite in Air**
Relative Intensity	0%	60%	100%	120%	180%	240%	300%	360%	420%	480%	530%
R₁
R₂

Calculated Properties of Zimbabweite

Electron Density:

Bulk Density (Electron Density)=5.37 gm/cc
note: Specific Gravity of Zimbabweite =6.20 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_Zimbabweite= 726.01 barns/electron
U=PE_Zimbabweite x r_electron=3,898.95 barns/cc.

Radioactivity:

GRapi = 16.29 (Gamma Ray American Petroleum Institute Units)
Concentration of Zimbabweite per GRapi unit = 6.14 (%)

Estimated Radioactivity from Zimbabweite - barely detectable

Zimbabweite Classification

Dana Class:

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

(08.07)Dana Type

(08.07.10)Dana Group

08.07.10.01 Zimbabweite Na(Pb,Na,K)2(Ta,Nb,Ti)4As4O18 Ccmb 2/m 2/m 2/m

Strunz Class:

04.JA.40 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.J - Arsenites, Antimonites, Bismuthites, Sulfites,

04.JA -Arsenites, antimonites, bismuthites; without additional anions, without H2O

04.JA.40 Zimbabweite Na(Pb,Na,K)2(Ta,Nb,Ti)4As4O18 Ccmb 2/m 2/m 2/m

Other Zimbabweite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(AntBidBlaNic3, Dana8)

See Also:

Links to other databases for Zimbabweite :
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 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - WWW-MINCRYST

Search for Zimbabweite using:

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

Visit our Advertisers for Zimbabweite :

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

Ask about Zimbabweite 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 Zimbabweite Specimen Label here :

Zimbabweite

Na(Pb,Na,K)2(Ta,Nb,Ti)4As+++4O18
Dana No: 08.07.10.01 Strunz No: 04.JA.40
Locality:

Notes: