Harkerite Mineral Data

General Harkerite Information

Chemical Formula:

Ca24Mg8Al2(SiO4)8(BO3)6(CO3)10•2(H2O)

Composition:

Molecular Weight = 2,935.91 gm

Calcium 32.76 % Ca 45.84 % CaO

Magnesium 6.62 % Mg 10.98 % MgO

Aluminum 1.84 % Al 3.47 % Al₂O₃

Silicon 7.65 % Si 16.37 % SiO₂

Boron 2.21 % B 7.11 % B₂O₃

Hydrogen 0.14 % H 1.23 % H₂O

Carbon 4.09 % C 14.99 % CO₂

Oxygen 44.69 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ca₂₄Mg₈Al₂(SiO₄)₈(BO₃)₆(CO₃)₁₀•2(H₂O)

Environment:

Skarns in dolomitic limestones at the contact with granite

IMA Status:

Valid Species (Pre-IMA) 1948

Locality:

Camas Malag, near Broadford, Isle of Skye, Scotland. Link to MinDat.org Location Data.

Name Origin:

Named for Alfred Harker (1859-1939), British petrologist, Cambridge University, Cambridge, England.

Name Pronunciation:

Harkerite + Pronunciation

Synonym:

ICSD 12105

PDF 10-465

Harkerite Image

Images:

Harkerite

Comments: B&W PPL image of harkerite (Hrk) and clintonite (Cln) aggregate with inclusions of spinel (Spl) in Crestmore marble #2A Mgt: magnetite, Anh: anhydrite, Cal: calcite.
Location: Low-pressure contact aureole in the Crestmore quarry, Riverside County, California, USA. (CanMin, v37:277). Scale: See Image.
© Canadian Mineralogist

Harkerite Crystallography

Axial Ratios:

a:c = 1:1.84545

Cell Dimensions:

a = 18.131, c = 33.46, Z = 6; V = 9,525.77 Den(Calc)= 3.07

Crystal System:

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

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

By Intensity(I/I_o): 2.61(1), 1.84(0.9), 2.13(0.8),

Physical Properties of Harkerite

Cleavage:

None

Color:

Colorless.

Density:

2.959

Diaphaneity:

Transparent

Luminescence:

Fluorescent, Long UV=weak dark red.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Harkerite

Dichroism (e):

colorless.

Dichroism (w):

colorless.

Gladstone-Dale:

CI meas= -0.045 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= -0.007 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2121,KPDmeas= 0.22,KC= 0.2106
Ncalc = 1.62 - 1.65

Optical Data:

Uniaxial (?), a=1.649-1.653, b=1.649-1.653, bire=0.0000.

Calculated Properties of Harkerite

Electron Density:

Bulk Density (Electron Density)=3.06 gm/cc
note: Specific Gravity of Harkerite =3.07 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Harkerite= 4.59 barns/electron
U=PE_Harkerite x rElectron Density= 14.06 barns/cc.

Radioactivity:

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

Harkerite Classification

Dana Class:

17.01.09.01 (17)Compound Carbonates

(17.01)with miscellaneous formulae

(17.01.09)Dana Group

17.01.09.01 Harkerite Ca24Mg8Al2(SiO4)8(BO3)6(CO3)10•2(H2O) R 3m 3 2/m

Strunz Class:

06.AB.70 06 - BORATES

06.A - Monoborates

06.AB -BO3, with additional anions; 1(D) + OH, etc.

06.AB.70 Harkerite Ca24Mg8Al2(SiO4)8(BO3)6(CO3)10•2(H2O) R 3m 3 2/m

Other Harkerite 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 Harkerite :
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 Harkerite Specimen Label here :

Harkerite

Ca24Mg8Al2(SiO4)8(BO3)6(CO3)10•2(H2O)
Dana No: 17.01.09.01 Strunz No: 06.AB.70
Locality:

Notes:

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