Gillespite Mineral Data

General Gillespite Information

Chemical Formula:

BaFe++Si4O10

Composition:

Molecular Weight = 465.51 gm

Barium 29.50 % Ba 32.94 % BaO

Iron 12.00 % Fe 15.43 % FeO

Silicon 24.13 % Si 51.63 % SiO₂

Oxygen 34.37 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

BaFe²⁺Si₄O₁₀

Environment:

In a glacial moraine (Dry Delta, Alaska, USA); probably from a contact metamorphic zone (Trumbull Peak, California, USA).

IMA Status:

Valid Species (Pre-IMA) 1922

Locality:

Dry Delta, Alaska Range, Alaska, USA. Link to MinDat.org Location Data.

Name Origin:

Named for Frank Gillespie, of Richardson, Alaska, USA, who discovered the first specimen.

Name Pronunciation:

Gillespite + Pronunciation

Gillespite Image

Images:

Anandite Gillespite

Comments: Black micaceous anandite with dark red gillespite.
Location: Esquire No. 7 Claim, Big Creek, Fresno County, California, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Images:

Gillespite Pellyite

Comments: Red crystalline gillespite with yellow pellyite rock matrix.
Location: GUN claims, Itsi Mountains, MacMillan Pass Area, Yukon Territory, Canada. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Images:

Bigcreekite Gillespite Sanbornite

Comments: Tiny white, spherical patterns, halo-like crystals of bigcreekite to about 0.5mm and reddish gillespite in a matrix of pale yellowish sanbornite.
Location: Trumbull Peak, Mariposa Co., California, United States. Scale: 2.5 x 2 x 2cm.
© Tom Loomis / Dakota Matrix

Gillespite Crystallography

Axial Ratios:

a:c = 1:2.13889

Cell Dimensions:

a = 7.5164, c = 16.0768, Z = 4; V = 908.28 Den(Calc)= 3.40

Crystal System:

Tetragonal - Ditetragonal Dipyramidal H-M Symbol (4/m 2/m 2/m) Space Group: P 4/ncc

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

By Intensity(I/I_o): 3.39(1), 3.22(0.7), 4.41(0.7),

Physical Properties of Gillespite

Cleavage:

{001} Good, {100} Good, {110} Poor

Color:

Red.

Density:

3.33

Diaphaneity:

Transparent to translucent

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Aggregates - Made of numerous individual crystals or clusters.

Hardness:

4 - Fluorite

Luminescence:

Non-fluorescent.

Luster:

Vitreous (Glassy)

Magnetism:

Nonmagnetic

Optical Properties of Gillespite

Dichroism (e):

red.

Dichroism (w):

colorless.

Gladstone-Dale:

CI meas= -0.043 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.021 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1824,KPDmeas= 0.1862,KC= 0.1786
Ncalc = 1.59 - 1.61

Optical Data:

Uniaxial (-), e=1.619, w=1.621, bire=0.0020.

Calculated Properties of Gillespite

Electron Density:

Bulk Density (Electron Density)=3.18 gm/cc
note: Specific Gravity of Gillespite =3.40 gm/cc.

Fermion Index:

Fermion Index = 0.06
Boson Index = 0.94

Photoelectric:

PE_Gillespite= 130.95 barns/electron
U=PE_Gillespite x rElectron Density= 417.00 barns/cc.

Radioactivity:

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

Gillespite Classification

Dana Class:

71.02.03.02 (71)Phyllosilicate Sheets of Six-Membered Rings

(71.02)with 2:1 Layers

(71.02.03)Cuprorivaite group

71.02.03.01 Cuprorivaite CaCuSi4O10 P 4/nnc 4/m 2/m 2/m

71.02.03.02 Gillespite BaFeSi4O10 P 4/ncc 4/m 2/m 2/m

71.02.03.03 Effenbergerite BaCuSi4O10 P 4/nnc 4/m 2/m 2/m

71.02.03.04 Wesselsite! SrCuSi4O10 P 4/ncc 4/m 2/m 2/m

Strunz Class:

09.EA.05 09 - SILICATES (Germanates)

09.E - Phyllosilicates

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

09.EA.05 Cuprorivaite CaCuSi4O10 P 4/nnc 4/m 2/m 2/m

09.EA.05 Effenbergerite BaCuSi4O10 P 4/nnc 4/m 2/m 2/m

09.EA.05 Gillespite BaFeSi4O10 P 4/ncc 4/m 2/m 2/m

09.EA.05 Wesselsite! SrCuSi4O10 P 4/ncc 4/m 2/m 2/m

Other Gillespite Information

References:

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

See Also:

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

Gillespite

BaFe++Si4O10
Dana No: 71.02.03.02 Strunz No: 09.EA.05
Locality:

Notes:

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