Mundrabillaite Mineral Data

General Mundrabillaite Information

Chemical Formula:

(NH4)2Ca(HPO4)2•(H2O)

Composition:

Molecular Weight = 286.13 gm

Calcium 14.01 % Ca 19.60 % CaO

Phosphorus 21.65 % P 49.61 % P₂O₅

Hydrogen 2.82 % H - % Calc as (NH₄)₂O

Hydrogen 1.41 % H 12.59 % H₂O

Nitrogen 9.79 % N 18.20 % (NH₄)₂O

Oxygen 50.33 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

(NH₄)₂Ca(HPO₄)₂•(H₂O)

Environment:

Found with other salts in the cave floor.

IMA Status:

Approved IMA 1983

Locality:

Petrogale Cave near Mundrabilla Station, WA, Australia. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Name Pronunciation:

Mundrabillaite + Pronunciation

Mundrabillaite Crystallography

Axial Ratios:

a:b:c =1.056:1:0.7833

Cell Dimensions:

a = 8.643, b = 8.184, c = 6.411, Z = 2; beta = 98° V = 449.06 Den(Calc)= 2.12

Crystal System:

Monoclinic Space Group: Pm,P 2,P 2/m

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

By Intensity(I/I_o): 4.279(1), 3.106(0.6), 3.687(0.4),

Physical Properties of Mundrabillaite

Color:

Colorless.

Density:

2.05

Diaphaneity:

Transparent to Translucent

Habit:

Microscopic Crystals - Crystals visible only with microscopes.

Hardness:

1-2 - Between Talc and Gypsum

Luster:

Earthy (Dull)

Streak:

white

Optical Properties of Mundrabillaite

Gladstone-Dale:

CI meas= -0.504 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.454 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2541,KPDmeas= 0.2628,KC= 0.1748
Ncalc = 1.36 - 1.37

Optical Data:

Biaxial (-), a=1.521-1.522, b=1.542-1.544, g=1.551-1.552, bire=0.0300, 2V(Calc)=60-64, 2V(Meas)=65.

Calculated Properties of Mundrabillaite

Electron Density:

Bulk Density (Electron Density)=2.19 gm/cc
note: Specific Gravity of Mundrabillaite =2.12 gm/cc.

Fermion Index:

Fermion Index = 0.09
Boson Index = 0.91

Photoelectric:

PE_{Mundrabillaite}= 2.74 barns/electron
U=PE_{Mundrabillaite} x rElectron Density= 6.01 barns/cc.

Radioactivity:

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

Mundrabillaite Classification

Dana Class:

39.03.03.01 (39)Hydrated Acid Phosphates, etc

(39.03)with miscellaneous formulae

(39.03.03)Dana Group

39.03.03.01 Mundrabillaite (NH4)2Ca(HPO4)2•(H2O) Pm,P 2,P 2/m Mono

Strunz Class:

08.CJ.10 08 - PHOSPHATES, ARSENATES, VANADATES

08.C - Phosphates without Additional Anions, with H2O

08.CJ -With only large cations

08.CJ.10 Mundrabillaite (NH4)2Ca(HPO4)2•(H2O) Pm,P 2,P 2/m Mono

08.CJ.10 Swaknoite (NH4)2Ca(HPO4)2•(H2O) Unk Ortho

Other Mundrabillaite Information

References:

NAME( Dana8) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Dana8)

See Also:

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

Mundrabillaite

(NH4)2Ca(HPO4)2•(H2O)
Dana No: 39.03.03.01 Strunz No: 08.CJ.10
Locality:

Notes:

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