Penikisite Mineral Data

General Penikisite Information

Chemical Formula:

BaMg2Al2(PO4)3(OH)3

Composition:

Molecular Weight = 583.72 gm

Barium 23.53 % Ba 26.27 % BaO

Magnesium 7.29 % Mg 12.08 % MgO

Aluminum 9.24 % Al 17.47 % Al₂O₃

Iron 2.39 % Fe 3.08 % FeO

Phosphorus 15.92 % P 36.48 % P₂O₅

Hydrogen 0.52 % H 4.63 % H₂O

Oxygen 41.11 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

BaMg_1.75Fe²⁺_0.25Al₂(PO₄)₃(OH)₃

Environment:

Forms a series with kulanite (Fe-end member).

IMA Status:

Approved IMA 1977

Locality:

Rapid Creek (Cross Cut Creek), Big fish River, Yukon Territory, Canada. Link to MinDat.org Location Data.

Name Origin:

Named for Gunar Penikis (1936-1979), who discovered the locality.

Name Pronunciation:

Penikisite + Pronunciation

Synonym:

IMA1976-023

Penikisite Image

Images:

Jagowerite Penikisite

Comments: Light green crystal of jagowerite intergrown with darker green penikisite in a tetrahedrite (black) and white quartz matrix.
Location: From quartz veins cutting clays 26 km N of Hess River, Yukon Territory, Canada. Scale: Sample size 2x1 cm.
© Dave Barthelmy

Penikisite Crystallography

Axial Ratios:

a:b:c =0.7456:1:0.4077

Cell Dimensions:

a = 8.999, b = 12.069, c = 4.921, Z = 2; alpha = 90°, beta = 100.517°, gamma = 90° V = 525.49 Den(Calc)= 3.69

Crystal System:

Triclinic - Pinacoidal H-M Symbol ( 1) Space Group: P1

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

By Intensity(I/I_o): 3.094(1), 2.915(0.8), 2.649(0.7),

Physical Properties of Penikisite

Cleavage:

{010} Good, {110} Good

Color:

Blue, Green.

Density:

3.79

Diaphaneity:

Transparent to Translucent

Habit:

Platy - Sheet forms (e.g. micas).

Habit:

Rosette - Bundled tabular aggregates resembling rose flower petals.

Hardness:

4 - Fluorite

Luminescence:

Non-fluorescent.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Penikisite

Gladstone-Dale:

CI meas= -0.002 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= -0.03 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1876,KPDmeas= 0.1827,KC= 0.1822
Ncalc = 1.67 - 1.69

Optical Data:

Biaxial (+), a=1.684, b=1.688, g=1.705, bire=0.0210, 2V(Calc)=54, 2V(Meas)=52-56. Dispersion r > v.

Pleochroism (x):

grass green.

Pleochroism (y):

blue green.

Pleochroism (z):

pale pink.

Calculated Properties of Penikisite

Electron Density:

Bulk Density (Electron Density)=3.60 gm/cc
note: Specific Gravity of Penikisite =3.79 gm/cc.

Fermion Index:

Fermion Index = 0.04
Boson Index = 0.96

Photoelectric:

PE_Penikisite= 101.16 barns/electron
U=PE_Penikisite x rElectron Density= 364.53 barns/cc.

Radioactivity:

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

Penikisite Classification

Dana Class:

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

(41.09)where (A B)5 (XO4)3 Zq

(41.09.01)Kulanite Group

41.09.01.01 Kulanite Ba(Fe,Mn,Mg)2Al2(PO4)3(OH)3 P 2₁/m 2/m

41.09.01.02 Penikisite BaMg2Al2(PO4)3(OH)3 P1 1

41.09.01.03 Bjarebyite (Ba,Sr)(Mn,Fe,Mg)2Al2(PO4)3(OH)3 P 2₁/m 2/m

41.09.01.04 Perloffite Ba(Mn,Fe)2Fe2(PO4)3(OH)3 P 2₁/m 2/m

41.09.01.05 Johntomaite! Ba(Fe,Ca,Mn)2Fe2(PO4)3(OH)3 P 2₁/m 2/m

Strunz Class:

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

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

08.BH -With medium-sized and large cations, (OH,etc.):RO4 = 1:1

08.BH.20 Bjarebyite (Ba,Sr)(Mn,Fe,Mg)2Al2(PO4)3(OH)3 P 2₁/m 2/m

08.BH.20 Kulanite Ba(Fe,Mn,Mg)2Al2(PO4)3(OH)3 P 2₁/m 2/m

08.BH.20 Penikisite BaMg2Al2(PO4)3(OH)3 P1 1

08.BH.20 Perloffite Ba(Mn,Fe)2Fe2(PO4)3(OH)3 P 2₁/m 2/m

08.BH.20 Johntomaite! Ba(Fe,Ca,Mn)2Fe2(PO4)3(OH)3 P 2₁/m 2/m

Other Penikisite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8)

See Also:

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

Penikisite

BaMg2Al2(PO4)3(OH)3
Dana No: 41.09.01.02 Strunz No: 08.BH.20
Locality:

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