Holtedahlite Mineral Data

General Holtedahlite Information

Chemical Formula:

Mg12(PO3OH,CO3)(PO4)5(OH,O)6

Composition:

Molecular Weight = 953.53 gm

Magnesium 30.59 % Mg 50.72 % MgO

Phosphorus 18.68 % P 42.80 % P₂O₅

Hydrogen 0.50 % H 4.49 % H₂O

Carbon 0.31 % C 1.15 % CO₂

Oxygen 49.92 % O

______ ______

100.00 % 99.16 % = TOTAL OXIDE

Empirical Formula:

Mg₁₂(PO₃OH)_0.75(CO₃)_0.25(PO₄)₅(OH)₄O₂

Environment:

Serpentine-magnesite deposit.

IMA Status:

Approved IMA 1979

Locality:

Tingelstadtjern quarry, Modum, Norway. Link to MinDat.org Location Data.

Name Origin:

Named for Olaf Holtedahl (1885-1975), Professor of Geology, University of Oslo, Oslo, Norway.

Name Pronunciation:

Holtedahlite + Pronunciation

Synonym:

ICSD 67048

PDF 33-879

Holtedahlite Image

Images:

Holtedahlite

Comments: Colorless glassy crystalline granular holtedahlite (appears gray in image) with yellow serpentinite rock and white apatite.
Location: Tingelstadtjern, Modum, Buskerud, Norway. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Holtedahlite Crystallography

Axial Ratios:

a:c = 1:0.44425

Cell Dimensions:

a = 11.203, c = 4.977, Z = 1; V = 540.96 Den(Calc)= 2.93

Crystal System:

Trigonal - Ditrigonal Pyramidal H-M Symbol (3m) Space Group: P 3₁m

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

By Intensity(I/I_o): 2.438(1), 3.722(0.9), 3.475(0.5),

Physical Properties of Holtedahlite

Cleavage:

None

Color:

Colorless.

Density:

2.94

Diaphaneity:

Transparent

Fracture:

Uneven - Flat surfaces (not cleavage) fractured in an uneven pattern.

Hardness:

4.5-5 - Near Apatite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Holtedahlite

Gladstone-Dale:

CI meas= -0.03 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.034 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2041,KPDmeas= 0.2034,KC= 0.1975
Ncalc = 1.58

Optical Data:

Uniaxial (-), e=1.597, w=1.599, bire=0.0020.

Calculated Properties of Holtedahlite

Electron Density:

Bulk Density (Electron Density)=2.93 gm/cc
note: Specific Gravity of Holtedahlite =2.94 gm/cc.

Fermion Index:

Fermion Index = 0.03
Boson Index = 0.97

Photoelectric:

PE_Holtedahlite= 1.59 barns/electron
U=PE_Holtedahlite x rElectron Density= 4.64 barns/cc.

Radioactivity:

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

Holtedahlite Classification

Dana Class:

41.06.04.02 (41)Anhydrous Phosphates, etc. Containing Hydroxyl or Halogen

(41.06)where (A)2 (XO4) Zq

(41.06.04)Satterlyite Group

41.06.04.01 Satterlyite (Fe,Mg)2(PO4)(OH) P 3₁m 3m

41.06.04.02 Holtedahlite Mg12(PO3OH,CO3)(PO4)5(OH,O)6 P 3₁m 3m

Strunz Class:

08.BB.20 08 - PHOSPHATES, ARSENATES, VANADATES

08.B - Phosphates, etc. with Additional Anions, without H2O

08.BB -With only medium-sized cations, (OH, etc.):RO4 � 1:1

08.BB.20 Holtedahlite Mg12(PO3OH,CO3)(PO4)5(OH,O)6 P 3₁m 3m

08.BB.20 Satterlyite (Fe,Mg)2(PO4)(OH) P 3₁m 3m

Other Holtedahlite Information

References:

NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

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

Holtedahlite

Mg12(PO3OH,CO3)(PO4)5(OH,O)6
Dana No: 41.06.04.02 Strunz No: 08.BB.20
Locality:

Notes:

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