Hawthorneite Mineral Data

General Hawthorneite Information

Chemical Formula:

Ba[Ti3Cr4Fe4Mg]O19

Composition:

Molecular Weight = 1,040.63 gm

Barium 13.20 % Ba 14.73 % BaO

Magnesium 2.34 % Mg 3.87 % MgO

Titanium 13.80 % Ti 23.03 % TiO₂

Chromium 19.99 % Cr 26.14 % CrO

Iron 21.47 % Fe 27.62 % FeO

Oxygen 29.21 % O

______ ______

100.00 % 95.39 % = TOTAL OXIDE

Empirical Formula:

BaTi₃Cr₄Fe²⁺₄MgO₁₉

Environment:

Formed during upper-mantle (75-100 km, 900-1,000 Deg C., 20-30 kbar) metasomatism of chromian spinel in peridotite xenolith in a kimberlite pipe. Included in spinel surrounded by li ndsleyite.

IMA Status:

Approved IMA 1989

Locality:

Bultfontein diamond mine, Kimberley, Cape Province, South Africa. Link to MinDat.org Location Data.

Name Origin:

Named for John Barry Hawthorne, formerly chief geologist (Diamonds), DeBeers Consolidated Mines, South Africa.

Name Pronunciation:

Hawthorneite + Pronunciation

Synonym:

ICSD 202256

PDF 46-1469

Hawthorneite Image

Images:

Hawthorneite

Comments: Replacement-textured magnesian chromian spinel (dark gray, CHR) infiltrated by hawthorneite (H, medium gray). B&W polished section, PPL with oil immersion. (AmMin, v74:668).
Location: Metasomatized, harzburgitic xenolith from a diamondiferous kimberlite pipe in Kimberley, South Africa. Scale: See Image.
© American Mineralogist

Hawthorneite Crystallography

Axial Ratios:

a:c = 1:3.92778

Cell Dimensions:

a = 5.871, c = 23.06, Z = 2; V = 688.36 Den(Calc)= 5.02

Crystal System:

Hexagonal - Dihexagonal Dipyramidal H-M Symbol (6/m 2/m 2/m) Space Group: P 6₃/mmc

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

By Intensity(I/I_o): 2.616(1), 2.765(0.85), 2.414(0.49),

Physical Properties of Hawthorneite

Cleavage:

None

Color:

Black, Brown.

Diaphaneity:

Opaque

Habit:

Granular - Generally occurs as anhedral to subhedral crystals in matrix.

Habit:

Inclusions - Generally found as inclusions in other minerals.

Hardness:

6-6.5 - Orthoclase-Pyrite

Luster:

Metallic

Optical Properties of Hawthorneite

Optical Data:

Uniaxial (-).

NCalc= 2.11 - from Gladstone-Dale relationship (KC = 0.2218) where Ncalc=Dcalc*KC+1

RL Anisotrophism:

Weak to moderate, in browns and grays.

RL Bireflectance:

Weak to moderate.

RL Color:

Light gray.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Hawthorneite in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
400 nm	19.50	18.10
420 nm	19.10	17.80
440 nm	18.80	17.50
460 nm	18.40	17.20
480 nm	18.10	17.00
500 nm	17.90	16.80
520 nm	17.70	16.60
540 nm	17.60	16.50
560 nm	17.40	16.40
580 nm	17.30	16.30
600 nm	17.20	16.20
620 nm	17.20	16.20
640 nm	17.10	16.10
660 nm	17.00	16.00
680 nm	17.00	16.00
700 nm	16.90	15.90

**Calculated Relative Intensity Colors of Hawthorneite in Air**
Relative Intensity	0%	60%	100%	120%	180%	240%	300%	360%	420%	480%	540%
R₁
R₂

Calculated Properties of Hawthorneite

Electron Density:

Bulk Density (Electron Density)=4.69 gm/cc
note: Specific Gravity of Hawthorneite =5.02 gm/cc.

Fermion Index:

Fermion Index = 0.06
Boson Index = 0.94

Photoelectric:

PE_Hawthorneite= 70.35 barns/electron
U=PE_Hawthorneite x rElectron Density= 329.88 barns/cc.

Radioactivity:

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

Hawthorneite Classification

Dana Class:

07.04.01.03 (07)Multiple Oxides

(07.04)with O19 groups

(07.04.01)(Hexagonal, P63/mmc)

07.04.01.01 Hibonite (Ca,Ce)(Al,Ti,Mg)12O19 P 6₃/mmc 6/m 2/m 2/m

07.04.01.02 Yimengite K(Cr,Ti,Fe,Mg)12O19 P 6₃/mmc 6/m 2/m 2/m

07.04.01.03 Hawthorneite Ba[Ti3Cr4Fe4Mg]O19 P 6₃/mmc 6/m 2/m 2/m

Strunz Class:

04.CC.45 04 - OXIDES (Hydroxides, V[5,6] vanadates, arsenites, antimonites, bismuthites, sulfites, selenites, tellurites, iodate

04.C - Metal:Oxygen = 2:3, 3:5, and Similar

04.CC -With large and medium-sized cations

04.CC.45 Hawthorneite Ba[Ti3Cr4Fe4Mg]O19 P 6₃/mmc 6/m 2/m 2/m

04.CC.45 Diaoyudaoite NaAl11O17 P 6₃/mmc 6/m 2/m 2/m

04.CC.45 Magnetoplumbite Pb(Fe,Mn)12O19 P 6₃/mmc 6/m 2/m 2/m

04.CC.45 Haggertyite! Ba[Fe6Ti5Mg]O19 P 6₃/mmc 6/m 2/m 2/m

04.CC.45 Batiferrite! Ba(Ti2Fe8Fe2)O19 P 6₃/mmc 6/m 2/m 2/m

04.CC.45 Hibonite (Ca,Ce)(Al,Ti,Mg)12O19 P 6₃/mmc 6/m 2/m 2/m

04.CC.45 Nezilovite! PbZn2(Mn,Ti)2Fe8O19 P 6₃/mmc 6/m 2/m 2/m

04.CC.45 Lindqvistite Pb2(Mn,Mg)Fe16027 P 6₃/mmc 6/m 2/m 2/m

04.CC.45 Plumboferrite Pb2Fe(11-x)MnxO19-2x(x=1/3) P 6₃/mmc 6/m 2/m 2/m

04.CC.45 Yimengite K(Cr,Ti,Fe,Mg)12O19 P 6₃/mmc 6/m 2/m 2/m

Other Hawthorneite Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Am.Min.,Vol.74,p668-675,1989) OPTIC PROP.(AntBidBlaNic3)

See Also:

Links to other databases for Hawthorneite :
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

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Hawthorneite

Ba[Ti3Cr4Fe4Mg]O19
Dana No: 07.04.01.03 Strunz No: 04.CC.45
Locality:

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