Tunisite Mineral Data

Tunisite Mineral Data +

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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

IMA Status:

Approved IMA 1969

Locality:

Link to MinDat.org Location Data.

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 DipyramidalH-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),

Crystal Structure:

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drag1 - LMB Manipulate Structure
drag2 - RMB Resize/Rotate
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H - Help Screen
I - Data Info
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Effenberger H , Kluger F , Pertlik F , Zemann J , Tschermaks Mineralogische und Petrographische Mitteilungen , 28 (1981) p.65-77, Tunisit: kristallstruktur und revision der chemischen formel

Physical Properties of Tunisite

Cleavage:

[???] Perfect

Color:

Colorless, White.

Density:

2.51

Diaphaniety:

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

Optical Data:

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

Calculated Properties of Tunisite

Electron Density:

r_electron=2.52 gm/cc
note: r_Tunisite=2.51 gm/cc.

Fermion Index

Fermion Index = 0.00127
Boson Index = 0.99873

Photoelectric:

PE_Tunisite= 2.63 barns/electron
U=PE_Tunisite x r_electron= 6.62 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Tunisite is Not Radioactive

Tunisite Classification

Dana Class:

16a.5.2.1 (16a)Carbonates - Hydroxyl or Halogen

(16a.5)with miscellaneous formulae

(16a.5.2)Dana Group

16a.5.2.1 Tunisite NaCa2Al4(CO3)4(OH)8Cl P 4/nmm 4/m 2/m 2/m

Strunz Class:

V/C.02-30 V - Nitrates, Carbonates and Borates

V/C - Waterfree carbonates with unfamiliar anions

V/C.02 - Barentsite - Tunisite series

V/C.02-10 Barentsite Na7AlH2(CO3)4F4 P1 or P1 Tri

V/C.02-20 Dawsonite NaAl(CO3)(OH)2 Imam 2/m 2/m 2/m

V/C.02-30 Tunisite NaCa2Al4(CO3)4(OH)8Cl P 4/nmm 4/m 2/m 2/m

Other Tunisite Information

References:

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 -Google Images 5 -Google Scholar 6 -Handbook of Mineralogy (UofA) 7 -MinDAT 8 -MinMax(Deutsch) 9 -MinMax(English) 10 -Mineralienatlas (Deutsch) 11 -QUT Mineral Atlas 12 - WWW-MINCRYST 13 -École des Mines de Paris

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

Tunisite

NaCa2Al4(CO3)4(OH)8Cl
Dana No: 16a.5.2.1 Strunz No: V/C.02-30
Locality:

Notes: