Pseudosinhalite Mineral Data

General Pseudosinhalite Information

Chemical Formula:

Mg2Al3B2O9(OH)

Composition:

Molecular Weight = 312.18 gm

Magnesium 15.57 % Mg 25.82 % MgO

Aluminum 25.93 % Al 48.99 % Al₂O₃

Boron 6.93 % B 22.30 % B₂O₃

Hydrogen 0.32 % H 2.89 % H₂O

Oxygen 51.25 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Mg₂Al₃B₂O₉(OH)

Environment:

Associated with hydrotalcite and occurs at the Tayozhnoye Fe-B skarn as a toptactic, retrograde replacement of sinhalite in metasomatized marble.

IMA Status:

Approved IMA 1999 (Dana # Added)

Locality:

Aldan Shield, southern Sakha - Yakutia Republic, Russian Federation. Link to MinDat.org Location Data.

Name Origin:

The name alludes to the optical, chemical, and structural similarity to sinhalite.

Name Pronunciation:

Pseudosinhalite + Pronunciation

Synonym:

IMA1997-014

Pseudosinhalite Crystallography

Axial Ratios:

a:b:c =1.7297:1:2.2748

Cell Dimensions:

a = 7.49, b = 4.33, c = 9.85, Z = 2; beta = 110.7° V = 298.83 Den(Calc)= 3.47

Crystal System:

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

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

By Intensity(I/I_o): 1.625(1), 2.14(1), 2.102(0.6),

Physical Properties of Pseudosinhalite

Cleavage:

None

Color:

Colorless.

Density:

3.608 - 3.508, Average = 3.55

Diaphaneity:

Transparent

Fracture:

Conchoidal - Fractures developed in brittle materials characterized by smoothly curving surfaces, (e.g. quartz).

Habit:

Pseudomorphous - Occurs in the form of another mineral.

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Pseudosinhalite

Gladstone-Dale:

CI meas= 0.052 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.028 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.205,KPDmeas= 0.1999,KC= 0.2108
Ncalc = 1.73 - 1.76

Optical Data:

Biaxial (-), a=1.691, b=1.713, g=1.73, bire=0.0390

Calculated Properties of Pseudosinhalite

Electron Density:

Bulk Density (Electron Density)=3.42 gm/cc
note: Specific Gravity of Pseudosinhalite =3.47 gm/cc.

Fermion Index:

Fermion Index = 0.02
Boson Index = 0.98

Photoelectric:

PE_{Pseudosinhalite}= 1.18 barns/electron
U=PE_{Pseudosinhalite} x rElectron Density= 4.05 barns/cc.

Radioactivity:

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

Pseudosinhalite Classification

Dana Class:

25.08.03.01 (25)Anhydrous Borates Containing Hydroxyl or Halogen

(25.08)Dana Type

(25.08.03)Dana Group

25.08.03.01 Pseudosinhalite! Mg2Al3B2O9(OH) P 2₁/c 2/m

Strunz Class:

06.AC.10 06 - BORATES

06.A - Monoborates

06.AC -B(O,OH)4, without and with additional anions; 1(T), 1(T)+OH, etc.

06.AC.10 Pseudosinhalite! Mg2Al3B2O9(OH) P 2₁/c 2/m

Other Pseudosinhalite Information

References:

NAME( AmMin, Vol 84, No. 7-8) PHYS. PROP.(AmMin, Vol 84, No. 7-8) OPTIC PROP.(MinRec)

See Also:

Links to other databases for Pseudosinhalite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - Handbook of Mineralogy (MinSocAm)
7 - Handbook of Mineralogy (UofA)
8 - MinDAT
9 - Mineralienatlas (Deutsch)
10 - Online Mineral Museum
11 - QUT Mineral Atlas
12 - Ruff.Info
13 - WWW-MINCRYST

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Print or Cut-and-Paste your Pseudosinhalite Specimen Label here :

Pseudosinhalite

Mg2Al3B2O9(OH)
Dana No: 25.08.03.01 Strunz No: 06.AC.10
Locality:

Notes:

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