Sinkankasite Mineral Data

General Sinkankasite Information

Chemical Formula:

H2MnAl(PO4)2(OH)•6(H2O)

Composition:

Molecular Weight = 398.98 gm

Manganese 13.77 % Mn 17.78 % MnO

Aluminum 6.76 % Al 12.78 % Al₂O₃

Phosphorus 15.53 % P 35.58 % P₂O₅

Hydrogen 3.79 % H 33.87 % H₂O

Oxygen 60.15 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

H₂Mn²⁺Al(PO₄)₂(OH)•6(H₂O)

Environment:

Pseudomorphs after triphylite and alterations of the same.

IMA Status:

Approved IMA 1984

Locality:

Barker pegmatite, SW of Keystone, Penninton County, South Dakota, USA. Link to MinDat.org Location Data.

Name Origin:

Named for John Sinkankas (1915-2002), Captain, U.S. Navy, and author of books on minerals and gems.

Name Pronunciation:

Sinkankasite + Pronunciation

Synonym:

ICSD 80126

PDF 42-597

Sinkankasite Image

Images:

Sinkankasite

Comments: White crystalline spray of acicular sinkankasite to 1mm on matrix.
Location: Barker mine, Keystone, Pennington County, South Dakota, USA. Scale: Picture size 5 mm.
© Tom Loomis / Dakota Matrix

Sinkankasite Crystallography

Axial Ratios:

a:b:c =0.9785:1:0.7027

Cell Dimensions:

a = 9.58, b = 9.79, c = 6.88, Z = 2; alpha = 108.1°, beta = 99.6°, gamma = 98.7° V = 597.79 Den(Calc)= 2.22

Crystal System:

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

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

By Intensity(I/I_o): 9.2(1), 5.06(0.6), 5.41(0.5),2.7(0.4), 2.83(0.4), 2.43(0.3), 2.94(0.3), 4.13(0.2),

Physical Properties of Sinkankasite

Cleavage:

{100} Good, {100} Parting

Color:

Colorless, White.

Density:

2.27

Diaphaneity:

Transparent to Translucent

Fracture:

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

Habit:

Pseudomorphous - Occurs in the form of another mineral.

Hardness:

4 - Fluorite

Luminescence:

Non-fluorescent.

Luster:

Vitreous - Dull

Streak:

white

Optical Properties of Sinkankasite

Gladstone-Dale:

CI meas= 0.038 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.025 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2357,KPDmeas= 0.2326,KC= 0.2417
Ncalc = 1.54 - 1.55

Optical Data:

Biaxial (-), a=1.511, b=1.529, g=1.544, bire=0.0330, 2V(Calc)=82, 2V(Meas)=84. Dispersion r < v.

Calculated Properties of Sinkankasite

Electron Density:

Bulk Density (Electron Density)=2.28 gm/cc
note: Specific Gravity of Sinkankasite =2.24 gm/cc.

Fermion Index:

Fermion Index = 0.0002944117
Boson Index = 0.9997055883

Photoelectric:

PE_Sinkankasite= 4.38 barns/electron
U=PE_Sinkankasite x rElectron Density= 9.98 barns/cc.

Radioactivity:

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

Sinkankasite Classification

Dana Class:

42.07.01.04 (42)Hydrated Phosphates, etc., Containing Hydroxyl or Halogen

(42.07)where (AB)5 (XO4)3 Zq ï¿½ x(H2O)

(42.07.01)Childrenite Group

42.07.01.01 Childrenite FeAl(PO4)(OH)2•(H2O) Bba2 mm2

42.07.01.02 Eosphorite MnAl(PO4)(OH)2•(H2O) Bbam 2/m 2/m 2/m

42.07.01.03 Ernstite (Mn1-xFex)Al(PO4)(OH)2-xOx C 2/c or Cc Mono

42.07.01.04 Sinkankasite H2MnAl(PO4)2(OH)•6(H2O) P1 1

Strunz Class:

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

08.D - Phosphates, etc

08.DB -With only medium-sized cations, (OH, etc.):RO4 < 1:1

08.DB.20 Sinkankasite H2MnAl(PO4)2(OH)•6(H2O) P1 1

Other Sinkankasite Information

References:

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

See Also:

Links to other databases for Sinkankasite :
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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Sinkankasite

H2MnAl(PO4)2(OH)•6(H2O)
Dana No: 42.07.01.04 Strunz No: 08.DB.20
Locality:

Notes:

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