Jaffeite Mineral Data

General Jaffeite Information

Chemical Formula:

Ca4(Si3O7)(OH)6

Composition:

Molecular Weight = 458.61 gm

Calcium 34.96 % Ca 48.91 % CaO

Silicon 18.37 % Si 39.30 % SiO₂

Hydrogen 1.32 % H 11.78 % H₂O

Oxygen 45.35 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₄(Si₃O₇)(OH)₆

Environment:

Naturally occurring analog of "TSH" (Tricalcium Silicate Hydrate), a component of portland cement.

IMA Status:

Approved IMA 1989

Locality:

Kombat mine, located 37 km east of Otavi and 49 km south of Tsumeb in the north-central part of Namibia. Link to MinDat.org Location Data.

Name Origin:

Named for Howard Jaffe of the University of Massachusetts.

Name Pronunciation:

Jaffeite

Synonym:

ICSD 39725

PDF 46-1285

Jaffeite Crystallography

Axial Ratios:

a:c = 1:0.74625

Cell Dimensions:

a = 10.026, c = 7.482, Z = 2; V = 651.33 Den(Calc)= 2.34

Crystal System:

Trigonal - Rhombohedral H-M Symbol ( 3) Space Group: P 3

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

By Intensity(I/I_o): 8.66(1), 2.833(0.9), 2.996(0.9),

Physical Properties of Jaffeite

Cleavage:

{???} Indistinct

Color:

Colorless.

Density:

2.65

Diaphaneity:

Transparent

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Jaffeite

Gladstone-Dale:

CI meas= -0.008 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.142 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2564,KPDmeas= 0.2264,KC= 0.2245
Ncalc = 1.53 - 1.6

Optical Data:

Uniaxial (+), w=1.596, e=1.604, bire=0.0080.

Calculated Properties of Jaffeite

Electron Density:

Bulk Density (Electron Density)=2.68 gm/cc
note: Specific Gravity of Jaffeite =2.65 gm/cc.

Fermion Index:

Fermion Index = 0.0092714039
Boson Index = 0.9907285961

Photoelectric:

PE_Jaffeite= 4.97 barns/electron
U=PE_Jaffeite x rElectron Density= 13.32 barns/cc.

Radioactivity:

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

Jaffeite Classification

Dana Class:

55.03.02.01 (55)Sorosilicate Si2O7 Groups, Generally with No Additional Anions

(55.03)with cations in [7] coordination

(55.03.02)Dana Group

55.03.02.01 Jaffeite Ca4(Si3O7)(OH)6 P 3 3

Strunz Class:

09.BE.12 09 - SILICATES (Germanates)

09.B - Sorosilicates

09.BE -Si2O7 groups with additional anions;

09.BE.12 Jaffeite Ca4(Si3O7)(OH)6 P 3 3

Other Jaffeite Information

References:

NAME( MinRec, v 22, p 422) PHYS. PROP.(Am.Min.,Vol.74,p1203-1206,1989) OPTIC PROP.(Am.Min.,Vol.74,p1203-1206,1989)

See Also:

Links to other databases for Jaffeite :
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 Jaffeite Specimen Label here :

Jaffeite

Ca4(Si3O7)(OH)6
Dana No: 55.03.02.01 Strunz No: 09.BE.12
Locality:

Notes:

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