Tumchaite Mineral Data

General Tumchaite Information

Chemical Formula:

Na2(Zr,Sn)Si4O11•2(H2O)

Composition:

Molecular Weight = 462.51 gm

Sodium 9.94 % Na 13.40 % Na₂O

Zirconium 14.79 % Zr 19.98 % ZrO₂

Silicon 24.29 % Si 51.96 % SiO₂

Tin 5.13 % Sn 6.52 % SnO₂

Hydrogen 0.87 % H 7.79 % H₂O

Oxygen 44.97 % O

______ ______

100.00 % 99.65 % = TOTAL OXIDE

Empirical Formula:

Na₂Zr_0.75Sn_0.2Si₄O₁₁•2(H₂O)

Environment:

From a core sample of rocks formed by the hydrothermal alteration of dolomite-calcite carbonatites. Zr-analogue of penkvilksite-1M

IMA Status:

Approved IMA 1999 (Dana # Added)

Locality:

Vuoriyarvi alkali-ultrabasic massif, North Karelia on the north shore of the Vuoriyarvi lake, Murmansk Region, Russia. Link to MinDat.org Location Data.

Name Origin:

The mineral is named for the river Tumcha near Vuoriyarvi massif.

Synonym:

ICSD 89740

IMA1999-041

Tumchaite Image

Images:

Tumchaite

Comments: SEM photomicrograph of typical tumchaite crystals shaped by the prism {hkl}, and by two pinacoids {100} and {h0l}. Grains are tabular on (100), elongated along [001]. (AmMin 85:1517).
Location: Vuoriyarvi alkali-ultrabasic massif, Murmansk Region, Russia. Scale: See Image.
© American Mineralogist

Tumchaite Crystallography

Axial Ratios:

a:b:c =1.0369:1:0.8547

Cell Dimensions:

a = 9.144, b = 8.818, c = 7.537, Z = 2; beta = 113.22° V = 558.49 Den(Calc)= 2.75

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 2₁/c

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

By Intensity(I/I_o): 8.4(1)(100), 2.691(0.9)(131), 2.902(0.9)(211),3.401(0.9)(202), 5.38(0.9)(111), 4(0.8)(111), 2.19(0.7)(313,41

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

Subbotin V V , Merlino S , Pushcharovsky D Y , Pakhomovsky Y A , Ferro O , Bogdanova A N , Voloshin A V , Sorokhtina N V , Zubkova N V , American Mineralogist , 85 (2000) p.1516-1520, Tumchaite Na2(Zr,Sn)Si4O11.2H2O - a new mineral from carbonatites of the, Vuoriyarvi alkali-ultrabasic massif, Murmansk Region, Russia

Physical Properties of Tumchaite

Cleavage:

{100} Perfect

Color:

Colorless.

Density:

2.78

Diaphaneity:

Translucent to transparent

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Massive - Granular - Common texture observed in granite and other igneous rock.

Habit:

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

Hardness:

4.5 - Between Fluorite and Apatite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Tumchaite

Gladstone-Dale:

CI meas= 0.007 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.004 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2124,KPDmeas= 0.2101,KC= 0.2115
Ncalc = 1.58 - 1.59

Optical Data:

Biaxial (-), a=1.57, b=1.588, g=1.594, bire=0.0240

Calculated Properties of Tumchaite

Electron Density:

Bulk Density (Electron Density)=2.69 gm/cc
note: Specific Gravity of Tumchaite =2.75 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_Tumchaite= 35.05 barns/electron
U=PE_Tumchaite x rElectron Density= 94.21 barns/cc.

Radioactivity:

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

Tumchaite Classification

Dana Class:

70.02.02.02 (70)Inosilicate Column or Tube Structures

(70.02)with Si2O7 dimers

(70.02.02)Dana Group

70.02.02.01 Penkvilksite Na4(Ti,Zr)2[Si8O22]•4(H2O) P 2₁/c 2/m

70.02.02.02 Tumchaite! Na2(Zr,Sn)Si4O11•2(H2O) P 2₁/c 2/m

Strunz Class:

09.EA.60 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EA -Single nets of tetrahedra with 4-, 5-, (6-), and 8-membered rings

09.EA.60 Penkvilksite Na4(Ti,Zr)2[Si8O22]•4(H2O) P 2₁/c 2/m

09.EA.60 Tumchaite! Na2(Zr,Sn)Si4O11•2(H2O) P 2₁/c 2/m

Other Tumchaite Information

References:

NAME( AmMin, v 85, p 1516) PHYS. PROP.(AmMin, v 85, p 1516) OPTIC PROP.(AmMin, v 85, p 1516)

See Also:

Links to other databases for Tumchaite :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Athena
5 - GeoScienceWorld
6 - Google Images
7 - Google Scholar
8 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Online Mineral Museum
11 - QUT Mineral Atlas
12 - Ruff.Info
13 - WWW-MINCRYST

Search for Tumchaite using:

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

Visit our Advertisers for Tumchaite :

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

Ask about Tumchaite 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 Tumchaite Specimen Label here :

Tumchaite

Na2(Zr,Sn)Si4O11•2(H2O)
Dana No: 70.02.02.02 Strunz No: 09.EA.60
Locality:

Notes: