Lepkhenelmite-Zn Mineral Data

General Lepkhenelmite-Zn Information

Chemical Formula:

Ba2Zn(Ti,Nb)4(Si4O12)2(O,OH)4•7(H2O)

Composition:

Molecular Weight = 1,261.08 gm

Potassium 1.64 % K 1.98 % K₂O

Barium 9.91 % Ba 11.06 % BaO

Sodium 0.44 % Na 0.59 % Na₂O

Strontium 1.53 % Sr 1.81 % SrO

Calcium 0.83 % Ca 1.16 % CaO

Magnesium 0.02 % Mg 0.03 % MgO

Titanium 11.16 % Ti 18.62 % TiO₂

Manganese 0.61 % Mn 0.79 % MnO

Niobium 7.44 % Nb 10.64 % Nb₂O₅

Aluminum 0.21 % Al 0.40 % Al₂O₃

Zinc 2.96 % Zn 3.68 % ZnO

Iron 0.18 % Fe 0.23 % FeO

Silicon 17.37 % Si 37.16 % SiO₂

Hydrogen 1.33 % H 11.84 % H₂O

Oxygen 44.38 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ba_0.91K_0.53Ca_0.26Na_0.24Sr_0.22Zn_0.57Mn²⁺_0.14Fe²⁺_0.04Mg_0.01Ti_2.94Nb_1.01Si_7.8Al_0.1O₂₄ O_1.38(OH)_2.62ï¿½6.98(H₂O)

Environment:

A hydrothermal mineral in cavities of a eudialyte - aegirine - feldspar pegmatite. Kuzmenkoite subgroup with dominance of Zn in the D structural site.

IMA Status:

Approved IMA 2003 (Dana # Added)

Locality:

Lepkhe-Nelm Mountain, Lovozero alkaline massif, Kola Peninsula, Russia. Link to MinDat.org Location Data.

Name Origin:

Named after the locality and composition.

Synonym:

IMA2003-003

Lepkhenelmite-Zn Image

Images:

Lepkhenelmite-Zn

Comments: B&W image of fragments of lepkhenelmite-Zn.
Location: Lepkhe-Nel'm Mt., Lovozero, Kola, Russia. Scale: See Image.
© Diederik Visser

Lepkhenelmite-Zn Crystallography

Axial Ratios:

a:b:c =1.0354:1:0.561

Cell Dimensions:

a = 14.381, b = 13.889, c = 7.793, Z = 2; beta = 117.52° V = 1,380.43 Den(Calc)= 3.03

Crystal System:

Monoclinic - Domatic H-M Symbol (m) Space Group: Cm

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

By Intensity(I/I_o): 3.194(1)(421,402,400), 6.39(1)(201,200), 3.05(0.8)(241,240), 2.585(0.6)(242,241), 2.906(0.6)(422,420), 4.912(0.6)(021), 6.95(0.37)(020,001), 3.101(0.22)(041,022)

Physical Properties of Lepkhenelmite-Zn

Cleavage:

None

Color:

Pale brown.

Density:

2.96

Diaphaneity:

Transparent

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Hardness:

5 - Apatite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Lepkhenelmite-Zn

Gladstone-Dale:

CI meas= 0.031 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.053 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2387,KPDmeas= 0.2444,KC= 0.2522
Ncalc = 1.75 - 1.76

Optical Data:

Biaxial (+), a=1.683, b=1.692, g=1.795, bire=0.1120, 2V(Calc)=36, 2V(Meas)=30. Dispersion dispersion not observed.

Calculated Properties of Lepkhenelmite-Zn

Electron Density:

Bulk Density (Electron Density)=2.87 gm/cc
note: Specific Gravity of Lepkhenelmite-Zn =2.96 gm/cc.

Fermion Index:

Fermion Index = 0.04
Boson Index = 0.96

Photoelectric:

PE_{Lepkhenelmite-Zn}= 57.94 barns/electron
U=PE_{Lepkhenelmite-Zn} x r_electron= 166.45 barns/cc.

Radioactivity:

GRapi = 23.02 (Gamma Ray American Petroleum Institute Units)
Concentration of Lepkhenelmite-Zn per GRapi unit = 4.34 (%)

Estimated Radioactivity from Lepkhenelmite-Zn - barely detectable

Lepkhenelmite-Zn Classification

Dana Class:

60.01.03c.04 (60)Cyclosilicate Four-Membered Rings

(60.01)as Titanosilicates

(60.01.03c)Labuntsovite Group (Kuzmenkoite subgroup Monoclinic [C2/m])

60.01.03c.01 Kuzmenkoite-Mn! (K,Na)2(Mn,Fe)(Ti,Nb)4[Si4O12]2(OH)4•5(H2O) C 2/m 2/m

60.01.03c.02 Kuzmenkoite-Zn! K2Zn(Ti,Nb)4(Si4O12)2(OH,O)4•6-8(H2O) Cm m

60.01.03c.03 Karupmollerite-Ca! (Na,Ca,K)2Ca(Nb,Ti)4(Si4O12)2(O,OH)4•7(H2O) C 2/m 2/m

60.01.03c.04 Lepkhenelmite-Zn! Ba2Zn(Ti,Nb)4(Si4O12)2(O,OH)4•7(H2O) Cm m

Strunz Class:

09.CE.30c 09 - SILICATES (Germanates)

09.C - Cyclosilicates

09.CE -[Si4O12]8- 4-membered single rings (vierer-Einfachringe),

09.CE.30c Gjerdingenite-Mn! (K,Na)2(Mn,Fe)(Nb,Ti)4(Si4O12)2(O,OH)4•6(H2O) C 2/m 2/m

09.CE.30c Karupmollerite-Ca! (Na,Ca,K)2Ca(Nb,Ti)4(Si4O12)2(O,OH)4•7(H2O) C 2/m 2/m

09.CE.30c Kuzmenkoite-Zn! K2Zn(Ti,Nb)4(Si4O12)2(OH,O)4•6-8(H2O) Cm m

09.CE.30c Kuzmenkoite-Mn! (K,Na)2(Mn,Fe)(Ti,Nb)4[Si4O12]2(OH)4•5(H2O) C 2/m 2/m

09.CE.30c Gjerdingenite-Fe! K2[(H2O)2(Fe,Mn)][(Nb,Ti)4(Si4O12)2(O,OH)4]•4(H2O) C 2/m 2/m

09.CE.30c Lepkhenelmite-Zn! Ba2Zn(Ti,Nb)4(Si4O12)2(O,OH)4•7(H2O) Cm m

09.CE.30c Gjerdingenite-Ca! K2Ca(Nb,Ti)4(Si4O12)2(O,OH)4•6H2O C 2/m 2/m

09.CE.30c Gjerdingenite-Na! (K,Na)2Na(Nb,Ti)4(Si4O12)2(OH,O)4•5H2O C 2/m 2/m

09.CE.30c Burovaite-Ca! (K,Na)4Ca2(Ti,Nb)8[Si4O12]4(OH,O)8•12H2O C 2/m 2/m

Other Lepkhenelmite-Zn Information

References:

NAME( CanMin, 42:1913) PHYS. PROP.(CanMin, 42:1913) OPTIC PROP.(CanMin, 42:1913)

See Also:

Links to other databases for Lepkhenelmite-Zn :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info

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Lepkhenelmite-Zn

Ba2Zn(Ti,Nb)4(Si4O12)2(O,OH)4•7(H2O)
Dana No: 60.01.03c.04 Strunz No: 09.CE.30c
Locality:

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