Theophrastite Mineral Data

General Theophrastite Information

Chemical Formula:

Ni(OH)2

Composition:

Molecular Weight = 92.70 gm

Nickel 63.31 % Ni 80.57 % NiO

Hydrogen 2.17 % H 19.43 % H₂O

Oxygen 34.52 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ni(OH)₂

Environment:

Coatings in chromitite in lenses in serpentinites (

IMA Status:

Approved IMA 1981

Locality:

Verrnion district, 50 km west of Thessalonike, Macedonia, Greece. Link to MinDat.org Location Data.

Name Origin:

Named for Theophrastus, (ca. 371 BC-ca. 287 BC), the first Greek mineralogist.

Name Pronunciation:

Theophrastite + Pronunciation

Synonym:

ICSD 28101

PDF 14-117

Theophrastite Image

Images:

Theophrastite Chromite

Comments: Green pearly scaly theophrastite coatings on massive dark chromite.
Location: Vermion Region, near Thessaloniki, Kedriki Makedhonia, Greece. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Theophrastite Crystallography

Axial Ratios:

a:c = 1:1.47173

Cell Dimensions:

a = 3.131, c = 4.608, Z = 1; V = 39.12 Den(Calc)= 3.93

Crystal System:

Trigonal - Hexagonal Scalenohedral H-M Symbol (3 2/m) Space Group: P 3m1

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

By Intensity(I/I_o): 2.335(1), 4.61(0.95), 1.755(0.5),

Physical Properties of Theophrastite

Color:

Emerald green.

Density:

Diaphaneity:

Transparent

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Hardness:

3.5 - Copper Penny

Luster:

Vitreous (Glassy)

Streak:

light green

Optical Properties of Theophrastite

Gladstone-Dale:

CI meas= 0.087 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= 0.07 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1933,KPDmeas= 0.1899,KC= 0.2079
Ncalc = 1.82 - 1.83

Optical Data:

Uniaxial (+), w=1.759-1.76, e=1.759-1.76, bire=0.0000.

Calculated Properties of Theophrastite

Electron Density:

Bulk Density (Electron Density)=3.90 gm/cc
note: Specific Gravity of Theophrastite =3.93 gm/cc.

Fermion Index:

Fermion Index = 0.0073228105
Boson Index = 0.9926771895

Photoelectric:

PE_{Theophrastite}= 24.82 barns/electron
U=PE_{Theophrastite} x rElectron Density= 96.81 barns/cc.

Radioactivity:

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

Theophrastite Classification

Dana Class:

06.02.01.05 (06)Hydroxides and Oxides Containing Hydroxyl

(06.02)where X++ (OH)2

(06.02.01)Brucite group (Rhombohedral: P-3m1)

06.02.01.01 Brucite Mg(OH)2 P 3m1 3 2/m

06.02.01.02 Amakinite (Fe,Mg)(OH)2 P 3m1 3 2/m

06.02.01.03 Pyrochroite Mn(OH)2 P 3m1 3 2/m

06.02.01.04 Portlandite Ca(OH)2 P 3m1 3 2/m

06.02.01.05 Theophrastite Ni(OH)2 P 3m1 3 2/m

Strunz Class:

04.FE.05 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.F - Hydroxides (without V or U)

04.FE -Hydroxides with OH, without H2O; sheets of edge-sharing octahedra

04.FE.05 Amakinite (Fe,Mg)(OH)2 P 3m1 3 2/m

04.FE.05 Brucite Mg(OH)2 P 3m1 3 2/m

04.FE.05 Portlandite Ca(OH)2 P 3m1 3 2/m

04.FE.05 Pyrochroite Mn(OH)2 P 3m1 3 2/m

04.FE.05 Theophrastite Ni(OH)2 P 3m1 3 2/m

04.FE.05 Fougerite! (Fe,Mg)6Fe2(OH)18•4(H2O) R 3m 3 2/m

Other Theophrastite Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Theophrastite :
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 - MinDAT
10 - Mineralienatlas (Deutsch)
11 - Online Mineral Museum
12 - QUT Mineral Atlas
13 - Ruff.Info
14 - WWW-MINCRYST

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

Theophrastite

Ni(OH)2
Dana No: 06.02.01.05 Strunz No: 04.FE.05
Locality:

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