Jonesite Mineral Data

General Jonesite Information

Chemical Formula:

Ba2(K,Na)[Ti2(Si5Al)O18•n(H2O)

Composition:

Molecular Weight = 914.93 gm

Potassium 3.21 % K 3.86 % K₂O

Barium 30.02 % Ba 33.52 % BaO

Sodium 0.63 % Na 0.85 % Na₂O

Titanium 10.47 % Ti 17.46 % TiO₂

Aluminum 2.95 % Al 5.57 % Al₂O₃

Silicon 15.35 % Si 32.84 % SiO₂

Hydrogen 0.66 % H 5.91 % H₂O

Oxygen 36.72 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Ba₂K_0.75Na_0.25Ti₂Si₅AlO₁₈•3(H₂O)

Environment:

In fractures and cavities of brecciated greenstone enclosed in blueschist associated with neptunite and joaquinite.

IMA Status:

Approved IMA 1977

Locality:

Dallas Gem Mine (Gem Mine; Benitoite Mine), New Idria District, San Benito Co., California, USA. Link to MinDat.org Location Data.

Name Origin:

Named for Francis Tucker Jones (1905-1993), Research Chemical Microscopist of Berkeley, California, USA, who discovered the mineral

Name Pronunciation:

Jonesite

Jonesite Image

Images:

Jonesite

Comments: Transparent, bladed crystal of jonesite on matrix.
Location: Dallas Gem Mine (Gem Mine; Benitoite Mine), New Idria District, San Benito Co., California, USA. Scale: Crystal size 3.5 mm.
© John Veevaert

Jonesite Crystallography

Axial Ratios:

a:b:c =0.4096:1:0.3354

Cell Dimensions:

a = 10.618, b = 25.918, c = 8.6945, Z = 4; beta = 127.633° V = 1,894.87 Den(Calc)= 3.21

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: P 2₁/m

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

By Intensity(I/I_o): 13(1), 3.03(0.45), 2.652(0.3),

Physical Properties of Jonesite

Cleavage:

{010} Distinct

Color:

Colorless.

Density:

3.25

Diaphaneity:

Transparent

Fracture:

Irregular - Flat surfaces (not cleavage) fractured in an irregular pattern.

Habit:

Bladed - Aggregates of thin lath-like crystals (e.g. kyanite).

Habit:

Tabular - Form dimensions are thin in one direction.

Hardness:

3-4 - Calcite-Fluorite

Luminescence:

Fluorescent, Short UV=dull orange.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Jonesite

Gladstone-Dale:

CI meas= 0.078 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= 0.067 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2059,KPDmeas= 0.2034,KC= 0.2206
Ncalc = 1.71 - 1.72

Optical Data:

Biaxial (+), a=1.641, b=1.66, g=1.682, bire=0.0410

Pleochroism (x):

colorless.

Pleochroism (y):

colorless.

Pleochroism (z):

colorless.

Calculated Properties of Jonesite

Electron Density:

Bulk Density (Electron Density)=3.02 gm/cc
note: Specific Gravity of Jonesite =3.21 gm/cc.

Fermion Index:

Fermion Index = 0.07
Boson Index = 0.93

Photoelectric:

PE_Jonesite= 130.86 barns/electron
U=PE_Jonesite x r_electron= 394.86 barns/cc.

Radioactivity:

GRapi = 43.46 (Gamma Ray American Petroleum Institute Units)
Concentration of Jonesite per GRapi unit = 2.30 (%)

Estimated Radioactivity from Jonesite - barely detectable

Jonesite Classification

Dana Class:

61.02.02.01 (61)Cyclosilicate Six-Membered Rings

(61.02)with Al substituted rings

(61.02.02)Dana Group

61.02.02.01 Jonesite Ba2(K,Na)[Ti2(Si5Al)O18•n(H2O) P 2₁/m 2/m

Strunz Class:

09.DJ.30 09 - SILICATES (Germanates)

09.D - Inosilicates* Structural terminology according to Liebau (1985)

09.DJ -Inosilicates with 4-periodic double and triple chains

09.DJ.30 Jonesite Ba2(K,Na)[Ti2(Si5Al)O18•n(H2O) P 2₁/m 2/m

Other Jonesite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990, AmMin, v 89, p 314) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

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

Jonesite

Ba2(K,Na)[Ti2(Si5Al)O18•n(H2O)
Dana No: 61.02.02.01 Strunz No: 09.DJ.30
Locality:

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