Bultfonteinite Mineral Data

General Bultfonteinite Information

Chemical Formula:

Ca2SiO2(OH,F)4

Composition:

Molecular Weight = 210.26 gm

Calcium 38.12 % Ca 53.34 % CaO

Silicon 13.36 % Si 28.58 % SiO₂

Hydrogen 1.44 % H 12.85 % H₂O

Oxygen 38.05 % O

Fluorine 9.04 % F 9.04 % F

- % F -3.80 % -O=F₂

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₂SiO₂(OH)₃F

Environment:

In a large "horse" of diabase and shale fragments in a kimberlite pipe.

IMA Status:

Valid Species (Pre-IMA) 1932

Locality:

In South Africa, in Cape Province, in the Bultfontein and Dutoitspan diamond mines, Kimberley. Link to MinDat.org Location Data.

Name Origin:

For the Bultfontein mine, Kimberley, South Africa, where it was first discovered.

Name Pronunciation:

Bultfonteinite + Pronunciation

Synonym:

ICSD 45301

PDF 42-1435

Bultfonteinite Image

Images:

Bultfonteinite

Comments: Rounded, spherical aggregation of acicular bultfonteinite crystals.
Location: N'Chwaning Mine, Kalahari Manganese Field, Northern Cape Province, South Africa. Scale: 8.5 x 4.6 cm.
© John Veevaert

Images:

Oyelite Bultfonteinite

Comments: White encrustation of oyelite covering brownish botryoidal bultfonteinite.
Location: N'Chwaning Mine, Kalahari Manganese Field, Northern Cape Province, South Africa. Scale: 2 x 4 cm.
© John Veevaert

Images:

Bultfonteinite Poldervaartite

Comments: Bow-tie clusters of white, acicular bultfonteinite and blocky, beige-colored poldervaartite on matrix.
Location: N'Chwaning mine, South Africa. Scale: picture size 4 cm.
© John Veevaert

Bultfonteinite Crystallography

Axial Ratios:

a:b:c =0.7459:1:0.508

Cell Dimensions:

a = 8.34, b = 11.18, c = 5.68, Z = 4; alpha = 91.983°, beta = 94.283°, gamma = 90.75° V = 527.77 Den(Calc)= 2.65

Crystal System:

Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1

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

By Intensity(I/I_o): 1.93(1), 2.92(0.6), 8.12(0.6),

Physical Properties of Bultfonteinite

Cleavage:

{010} Distinct, {100} Distinct

Color:

Colorless, Pink.

Density:

2.73

Diaphaneity:

Transparent

Hardness:

4.5 - Between Fluorite and Apatite

Streak:

white

Optical Properties of Bultfonteinite

Gladstone-Dale:

CI meas= 0.013 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.017 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2231,KPDmeas= 0.2166,KC= 0.2194
Ncalc = 1.58 - 1.6

Optical Data:

Biaxial (+), a=1.587, b=1.59, g=1.597, bire=0.0100

Calculated Properties of Bultfonteinite

Electron Density:

Bulk Density (Electron Density)=2.75 gm/cc
note: Specific Gravity of Bultfonteinite =2.73 gm/cc.

Fermion Index:

Fermion Index = 0.006937366
Boson Index = 0.993062634

Photoelectric:

PE_{Bultfonteinite}= 5.22 barns/electron
U=PE_{Bultfonteinite} x rElectron Density= 14.37 barns/cc.

Radioactivity:

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

Bultfonteinite Classification

Dana Class:

52.04.07.02 (52)Nesosilicate Insular SiO4 Groups and O, OH, F, and H2O

(52.04)with cations in [6] and/or > [6] coordination

(52.04.07)Afwillite and related species

52.04.07.01 Afwillite Ca3Si2O4(OH)6 P 2₁ 2

52.04.07.02 Bultfonteinite Ca2SiO2(OH,F)4 P1 1

52.04.07.03 Hatrurite Ca3SiO5 R 3m 3m

52.04.07.04 Jasmundite Ca11(SiO4)4O2S I 42m 4 2m

Strunz Class:

09.AG.80 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AG -Nesosilicates with additional anions; cations in > [6] ï¿½ [6] coordination

09.AG.80 Bultfonteinite Ca2SiO2(OH,F)4 P1 1

Other Bultfonteinite 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 Bultfonteinite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - Franklin Minerals(Dunn)
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info
16 - WWW-MINCRYST

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Bultfonteinite

Ca2SiO2(OH,F)4
Dana No: 52.04.07.02 Strunz No: 09.AG.80
Locality:

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