Jeppeite Mineral Data

Jeppeite Mineral Data +

General Jeppeite Information

Chemical Formula:

(K,Ba)2(Ti,Fe+++)6O13

Composition:

Molecular Weight = 641.51 gm

Potassium 7.31 % K 8.81 % K₂O

Barium 14.98 % Ba 16.73 % BaO

Titanium 41.80 % Ti 69.73 % TiO₂

Iron 3.48 % Fe 4.98 % Fe₂O₃

Oxygen 32.42 % O

______ ______

100.00 % 100.25 % = TOTAL OXIDE

Empirical Formula:

K_1.2Ba_0.7Ti_5.6Fe³⁺_0.4O₁₃

Environment:

In a large, weathered lamproite plug.

IMA Status:

Approved IMA 1984

Locality:

Wolgidee Hills, West Kimberley district, Western Australia. Link to MinDat.org Location Data.

Name Origin:

Named for John Frederick Biccard Jeppe (1920-), geologist of Nedlands, Western Australia, discoverer of the mineral.

Synonym:

ICSD 200005

PDF 37-426

Jeppeite Image

Images:

Jeppeite

Comments: Dark brown crystalline granular jeppeite.
Location: Walgidee Hills, Western Australia, Australia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Jeppeite Crystallography

Axial Ratios:

a:b:c =4.051:1:2.3777

Cell Dimensions:

a = 15.543, b = 3.8368, c = 9.123, Z = 2; beta = 99.25° V = 536.98 Den(Calc)= 3.97

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: C 2/m

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

By Intensity(I/I_o): 2.812(1), 2.99(1), 3.07(1),

Crystal Structure:

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Cid-Dresdner H , Buerger M J , Zeitschrift fur Kristallographie , 117 (1962) p.411-430, The crystal structure of potassium hexatitanate K2Ti6O13, Locality: synthetic

Physical Properties of Jeppeite

Cleavage:

[100] Perfect, [201] Good

Color:

Black.

Density:

3.94

Diaphaniety:

Opaque

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Hardness:

5-6 - Between Apatite and Orthoclase

Luster:

Sub Metallic

Streak:

light brown

Optical Properties of Jeppeite

Gladstone-Dale:

CI meas= 0.049 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.057 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.3098,KPDmeas= 0.3122,KC= 0.3284

Optical Data:

Biaxial (?), a=2.13, b=2.21, g=2.35, bire=0.2200

Pleochroism (x):

capri blue.

Pleochroism (y):

dark greenish brown.

Pleochroism (z):

dark olive buff.

RL Bireflectance:

Weak.

RL Color:

Gray, may have golden internal reflections.

Reflectivity

**Standardized Intensity (100%) Reflection Spectra of Jeppeite in Air**
λ	R₁	R₂	∑ R₁(λ)	∑ R₂(λ)
400 nm	16.10	19.50
420 nm	15.50	18.90
440 nm	15.00	18.40
460 nm	14.50	18.00
480 nm	14.20	17.60
500 nm	13.90	17.30
520 nm	13.60	17.00
540 nm	13.40	16.80
560 nm	13.20	16.60
580 nm	13.10	16.50
600 nm	13.00	16.40
620 nm	12.90	16.20
640 nm	12.90	16.20
660 nm	12.90	16.10
680 nm	12.80	16.00
700 nm	12.80	16.00

**Calculated Relative Intensity Colors of Jeppeite in Air**
Relative Intensity	0%	70%	100%	140%	210%	280%	350%	420%	490%	560%	630%	660%
R₁
R₂

Calculated Properties of Jeppeite

Electron Density:

r_electron=3.68 gm/cc
note: r_Jeppeite=3.94 gm/cc.

Fermion Index

Fermion Index = 0.08165
Boson Index = 0.91835

Photoelectric:

PE_Jeppeite= 73.28 barns/electron
U=PE_Jeppeite x r_electron= 269.69 barns/cc.

Radioactivity:

GRapi = 98.56 (Gamma Ray American Petroleum Institute Units)

Estimated Radioactivity from Jeppeite - barely detectable

Jeppeite Classification

Dana Class:

8.7.9.1 (8)Multiple Oxides with Nb, Ta, and Ti

(8.7)Dana Type

(8.7.9)Dana Group

8.7.9.1 Jeppeite (K,Ba)2(Ti,Fe)6O13 C 2/m 2/m

Strunz Class:

IV/D.07-10 IV - Oxides

IV/D - Oxides with metal : oxygen = 1:2 (MO2 and related compounds)

IV/D.07 - Cryptomelane group

IV/D.07-10 Jeppeite (K,Ba)2(Ti,Fe)6O13 C 2/m 2/m

Other Jeppeite Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(AntBidBlaNic3)

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Jeppeite

(K,Ba)2(Ti,Fe+++)6O13
Dana No: 8.7.9.1 Strunz No: IV/D.07-10
Locality:

Notes: