Tobelite Mineral Data

General Tobelite Information

Chemical Formula:

(NH4,K)Al2(Si3Al)O10(OH)2

Composition:

Molecular Weight = 376.27 gm

Potassium 2.08 % K 2.50 % K₂O

Aluminum 20.08 % Al 37.94 % Al₂O₃

Silicon 23.89 % Si 51.10 % SiO₂

Hydrogen 0.54 % H - % Calc as (NH₄)₂O

Hydrogen 0.54 % H 4.79 % H₂O

Nitrogen 1.86 % N 3.46 % (NH₄)₂O

Oxygen 51.03 % O

______ ______

100.00 % 99.79 % = TOTAL OXIDE

Empirical Formula:

(NH₄)_0.5K_0.2Al₂Si_3.2Al_0.8O₁₀(OH)₂

Environment:

Hydrothemal alteration of biotite andesite dike or in a hydrothermally altered rhyolite tuff.

IMA Status:

Approved IMA 1982

Locality:

Ohgidani pottery stone deposit, Tobe, Ehime Prefecture, adn in the Horo pryophyllite deposit, Toyosaka, hiroshima Prefecture, Japan. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Name Pronunciation:

Tobelite

Tobelite Image

Images:

Tobelite

Comments: Fine grained massive tobelite.
Location: Tobe, Ehime, Japan. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Tobelite Crystallography

Axial Ratios:

a:b:c =0.5807:1:1.1625

Cell Dimensions:

a = 5.219, b = 8.986, c = 10.447, Z = 2; beta = 101.31° V = 480.43 Den(Calc)= 2.60

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m

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

By Intensity(I/I_o): 10.24(1), 3.408(0.6), 2.566(0.45),

Physical Properties of Tobelite

Cleavage:

{001} Perfect

Color:

Yellowish green, Pearly white.

Density:

2.58

Diaphaneity:

Transparent

Habit:

Massive - Fibrous - Distinctly fibrous fine-grained forms.

Habit:

Scaly - Morphology like fish scales.

Hardness:

2 - Gypsum

Luster:

Vitreous - Silky

Streak:

white

Optical Properties of Tobelite

Gladstone-Dale:

CI meas= -0.083 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.074 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2213,KPDmeas= 0.2231,KC= 0.206
Ncalc = 1.53 - 1.54

Optical Data:

Biaxial (-), a=1.555-1.56, b=1.575-1.587, g=1.581-1.595, bire=0.0260-0.0350, 2V(Calc)=56, 2V(Meas)=28-30.

Calculated Properties of Tobelite

Electron Density:

Bulk Density (Electron Density)=2.61 gm/cc
note: Specific Gravity of Tobelite =2.60 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_Tobelite= 1.72 barns/electron
U=PE_Tobelite x r_electron= 4.49 barns/cc.

Radioactivity:

GRapi = 30.06 (Gamma Ray American Petroleum Institute Units)
Concentration of Tobelite per GRapi unit = 3.33 (%)

Estimated Radioactivity from Tobelite - barely detectable

Tobelite Classification

Dana Class:

71.02.02a.07 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.02)with 2:1 Layers

(71.02.02a)Mica Group (Muscovite subgroup)

71.02.02a.01 Muscovite KAl2(Si3Al)O10(OH,F)2 C 2/m 2/m

71.02.02a.02 Paragonite NaAl2(Si3Al)O10(OH)2 C 2/c,Cc Mono

71.02.02a.03 Chernykhite (Ba,Na)V,Al)2(Si,Al)4O10(OH)2 C 2/c 2/m

71.02.02a.04 Roscoelite K(V,Al,Mg)2AlSi3O10(OH)2 C 2/m 2/m

71.02.02a.05 Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2 C 2/m 2/m

71.02.02a.06 Celadonite K(Mg,Fe)(Fe,Al)[Si4O10](OH)2 C 2/m 2/m

71.02.02a.06b Ferroceladonite! K2FeFeSi8O20(OH)4 C 2/m 2/m

71.02.02a.06c Ferroaluminoceladonite! K2Fe2Al2Si8O20(OH)4 C 2/m 2/m

71.02.02a.06d Aluminoceladonite! KAl(Mg,Fe)[]Si4O10(OH)2 2/m

71.02.02a.06e Chromceladonite! KCrMg(Si4O10)(OH)2 C 2 2

71.02.02a.07 Tobelite (NH4,K)Al2(Si3Al)O10(OH)2 C 2/m 2/m

71.02.02a.08 Nanpingite Cs(Al,Mg,Fe,Li)2(Si3Al)O10(OH,F)2 C 2/c 2/m

71.02.02a.09 Boromuscovite KAl2(Si3B)O10(OH,F)2 C 2/m 2/m

71.02.02a.10 Montdorite (K,Na)(Fe,Mn,Mg)2.5[Si4O10](F,OH)2 C 2/c 2/m

71.02.02a.11 Chromphyllite! (K,Ba)(Cr,Al)2[AlSi3O10](OH,F)2 C 2c 2/m

71.02.02a.12 Shirokshinite! K(NaMg2)Si4O10F2 C 2/m 2/m

Strunz Class:

09.EC.15 09 - SILICATES (Germanates)

09.E - Phyllosilicates

09.EC -Phyllosilicates with mica sheets, composed of tetrahedral and octahedral nets

09.EC.15 Boromuscovite KAl2(Si3B)O10(OH,F)2 C 2/m 2/m

09.EC.15 Celadonite K(Mg,Fe)(Fe,Al)[Si4O10](OH)2 C 2/m 2/m

09.EC.15 Chernykhite (Ba,Na)V,Al)2(Si,Al)4O10(OH)2 C 2/c 2/m

09.EC.15 Chromphyllite! (K,Ba)(Cr,Al)2[AlSi3O10](OH,F)2 C 2c 2/m

09.EC.15 Glauconite (K,Na)(Fe,Al,Mg)2(Si,Al)4O10(OH)2 C 2/m 2/m

09.EC.15 Aluminoceladonite! KAl(Mg,Fe)[]Si4O10(OH)2 2/m

09.EC.15 Ferroaluminoceladonite! K2Fe2Al2Si8O20(OH)4 C 2/m 2/m

09.EC.15 Ferroceladonite! K2FeFeSi8O20(OH)4 C 2/m 2/m

09.EC.15 Montdorite (K,Na)(Fe,Mn,Mg)2.5[Si4O10](F,OH)2 C 2/c 2/m

09.EC.15 Nanpingite Cs(Al,Mg,Fe,Li)2(Si3Al)O10(OH,F)2 C 2/c 2/m

09.EC.15 Tobelite (NH4,K)Al2(Si3Al)O10(OH)2 C 2/m 2/m

09.EC.15 Roscoelite K(V,Al,Mg)2AlSi3O10(OH)2 C 2/m 2/m

09.EC.15 Muscovite KAl2(Si3Al)O10(OH,F)2 C 2/m 2/m

09.EC.15 Paragonite NaAl2(Si3Al)O10(OH)2 C 2/c,Cc Mono

09.EC.15 Tainiolite KLiMg2Si4O10F2 C 2/m 2/m

09.EC.15 Chromceladonite! KCrMg(Si4O10)(OH)2 C 2 2

09.EC.15 Ganterite! [Ba0.5(Na,K)0.5]Al2(Si2.5Al1.5O10)(OH)2 C 2/c 2/m

Other Tobelite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic2)

See Also:

Links to other databases for Tobelite :
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

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Tobelite

(NH4,K)Al2(Si3Al)O10(OH)2
Dana No: 71.02.02a.07 Strunz No: 09.EC.15
Locality:

Notes:

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