Tunisite Mineral Data

General Tunisite Information

Chemical Formula:

NaCa2Al4(CO3)4(OH)8Cl

Composition:

Molecular Weight = 622.62 gm

Sodium 3.69 % Na 4.98 % Na₂O

Calcium 12.87 % Ca 18.01 % CaO

Aluminum 17.33 % Al 32.75 % Al₂O₃

Hydrogen 1.30 % H 11.57 % H₂O

Carbon 7.72 % C 28.27 % CO₂

Chlorine 5.69 % Cl 5.69 % Cl

- % Cl -1.28 % -O=Cl₂

Oxygen 51.39 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

NaCa₂Al₄(CO₃)₄(OH)₈Cl

Environment:

Hydrothermal mineral, filling cavities in calcite.

IMA Status:

Approved IMA 1969

Locality:

Sakiet Sidi Yousseff Pb-Zn mine, between Le Kef and Souk Ahras, Tunisia. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Name Pronunciation:

Tunisite

Synonym:

ICSD 100720

PDF 27-1001

Tunisite Image

Images:

Tunisite

Comments: Transparent pearly platy tunisite microcrystal.
Location: Condorcet, Drome, France. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Tunisite Crystallography

Axial Ratios:

a:c = 1:0.58663

Cell Dimensions:

a = 11.22, c = 6.582, Z = 2; V = 828.60 Den(Calc)= 2.50

Crystal System:

Tetragonal - Ditetragonal Dipyramidal H-M Symbol (4/m 2/m 2/m) Space Group: P 4/nmm

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

By Intensity(I/I_o): 5.615(1), 2.592(0.9), 3.551(0.8),

Physical Properties of Tunisite

Cleavage:

{???} Perfect

Color:

Colorless, White.

Density:

2.51

Diaphaneity:

Transparent to Translucent

Hardness:

3.5-4.5 - Between Copper Penny and Fluorite-Apatite

Streak:

white

Optical Properties of Tunisite

Gladstone-Dale:

CI meas= -0.006 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.01 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2344,KPDmeas= 0.2335,KC= 0.2321
Ncalc = 1.58

Optical Data:

Uniaxial (+), w=1.573, e=1.599, bire=0.0260.

Calculated Properties of Tunisite

Electron Density:

Bulk Density (Electron Density)=2.52 gm/cc
note: Specific Gravity of Tunisite =2.51 gm/cc.

Fermion Index:

Fermion Index = 0.001271238
Boson Index = 0.998728762

Photoelectric:

PE_Tunisite= 2.63 barns/electron
U=PE_Tunisite x rElectron Density= 6.62 barns/cc.

Radioactivity:

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

Tunisite Classification

Dana Class:

16a.05.02.01 (16a)Carbonates - Hydroxyl or Halogen

(16a.05)with miscellaneous formulae

(16a.05.02)Dana Group

16a.05.02.01 Tunisite NaCa2Al4(CO3)4(OH)8Cl P 4/nmm 4/m 2/m 2/m

Strunz Class:

05.BB.15 05 - CARBONATES (NITRATES)

05.B - Carbonates with additional anions, without H2O

05.BB -With alkalies, etc.

05.BB.15 Tunisite NaCa2Al4(CO3)4(OH)8Cl P 4/nmm 4/m 2/m 2/m

Other Tunisite Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Tunisite :
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

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

Tunisite

NaCa2Al4(CO3)4(OH)8Cl
Dana No: 16a.05.02.01 Strunz No: 05.BB.15
Locality:

Notes:

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