Poldervaartite Mineral Data (original) (raw)

General Poldervaartite Information

Help on Chemical Formula: Chemical Formula:

(Ca,Mn++)2SiO3(OH)2

Help on Composition: Composition:

Molecular Weight = 197.68 gm

Calcium 30.41 % Ca 42.55 % CaO

Manganese 13.90 % Mn 17.94 % MnO

Silicon 14.21 % Si 30.39 % SiO2

Hydrogen 1.02 % H 9.11 % H2O

Oxygen 40.47 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Help on Empirical Formula: Empirical Formula:

Ca1.5Mn2+0.5SiO3(OH)2

Help on Environment: Environment:

In a pocket in massive manganese ores in a bedded manganese ore deposit.

Help on IMA Status: IMA Status:

Approved IMA 1993

Help on Locality: Locality:

Wessels mine, near Kuruman, Cape Province, South Africa. Link to MinDat.org Location Data.

Help on Name Origin: Name Origin:

Named for Arie Poldervaart (1918-1964), Professor of Petrology, Columbia University, New York City, New York, USA.

Help on Name Pronunciation: Name Pronunciation:

Poldervaartite + Pronunciation Say POLDERVAARTITE

Help on Synonym: Synonym:

ICSD 74005

IMA1992-012

PDF 46-1435

Poldervaartite Image

Click Here for Larger Poldervaartite Image in a New Browser Window Images:

Click Here for Larger Poldervaartite Image Poldervaartite Comments: Moderate reddish tint to yellowish poldervaartite crystalline druze on matrix. Location: N'chwaning II mine, section 5 south, stope 46-47 roof, Kuruman, Kalahari desert, South Africa.Scale: 6 x 3.5 x 4 cm. © Fabre Minerals

Click Here for Larger Poldervaartite Image in a New Browser Window Images:

Click Here for Larger Poldervaartite Image Poldervaartite Bultfonteinite 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

Poldervaartite Crystallography

Help on Axial Ratios: Axial Ratios:

a:b:c =1.0283:1:1.1527

Help on Cell Dimensions: Cell Dimensions:

a = 9.398, b = 9.139, c = 10.535, Z = 8; V = 904.83 Den(Calc)= 2.90

Help on Crystal System: Crystal System:

Orthorhombic - DipyramidalH-M Symbol (2/m 2/m 2/m) Space Group: P bca

Help on X Ray Diffraction: X Ray Diffraction:

By Intensity(I/Io): 3.231(1), 4.18(0.45), 2.846(0.42),

Click Here for Large Poldervaartite Structure Window Crystal Structure:

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Help on Above

| | Dai Y S , Harlow G E , McGhie A R , American Mineralogist , 78 (1993) p.1082-1087, Poldervaartite, Ca(Ca0.5Mn0.5)(SiO3OH)(OH), a new acid nesosilicate from the, Kalahari manganese field, South Africa: Crystal structure and description | | --------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------------- |

Physical Properties of Poldervaartite

Help on Cleavage: Cleavage:

None

Help on Color: Color:

Colorless, Milky white.

Help on Density: Density:

2.91

Help on Diaphaneity: Diaphaneity:

Transparent to Translucent

Help on Hardness: Hardness:

5 - Apatite

Help on Luster: Luster:

Vitreous (Glassy)

Help on Streak: Streak:

white

Optical Properties of Poldervaartite

Help on Gladstone-Dale: Gladstone-Dale:

CI meas= -0.01 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.013 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2218,KPDmeas= 0.2211,KC= 0.2189
Ncalc = 1.63 - 1.64

Help on Optical Data: Optical Data:

Biaxial (+), a=1.634, b=1.64, g=1.656, bire=0.0220, 2V(Calc)=64, 2V(Meas)=63-65.

Calculated Properties of Poldervaartite

Help on Electron Density: Electron Density:

Bulk Density (Electron Density)=2.90 gm/cc
note: Specific Gravity of Poldervaartite =2.91 gm/cc.

Help on Fermion Index: Fermion Index:

Fermion Index = 0.0072410959
Boson Index = 0.9927589041

Help on Photoelectric: Photoelectric:

PEPoldervaartite = 7.75 barns/electron
U=PEPoldervaartite x rElectron Density= 22.48 barns/cc.

Help on Radioactivity: Radioactivity:

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

Poldervaartite Classification

Help on Dana Class: Dana Class:

78.01.08.01 (78)Unclassified silicates

(78.01)possible nesosilicates

(78.01.08)Dana Group

78.01.08.01 Poldervaartite (Ca,Mn)2SiO3(OH)2 P bca 2/m 2/m 2/m

78.01.08.02 Olmiite! CaMn[SiO3(OH)](OH) P bca 2/m 2/m 2/m

Help on Strunz Class: Strunz Class:

09.AF.90 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AF -Nesosilicates with additional anions;

09.AF.90 Poldervaartite (Ca,Mn)2SiO3(OH)2 P bca 2/m 2/m 2/m

09.AF.90 Olmiite! CaMn[SiO3(OH)](OH) P bca 2/m 2/m 2/m

Other Poldervaartite Information

Help on References: References:

NAME( AntBidBlaNic2) PHYS. PROP.(Am.Min.,Vol.78,p1082-1087,1993) OPTIC PROP.(Am.Min.,Vol.78,p1082-1087,1993)

Help on See Also: See Also:

Links to other databases for Poldervaartite :
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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Ask about Poldervaartite here :
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Print or Cut-and-Paste your Poldervaartite Specimen Label here :

Poldervaartite

(Ca,Mn++)2SiO3(OH)2
Dana No: 78.01.08.01 Strunz No: 09.AF.90
Locality:

Notes: