Mawbyite Mineral Data

General Mawbyite Information

Chemical Formula:

Pb(Fe+++Zn)2(AsO4)2(OH,H2O)2

Composition:

Molecular Weight = 649.02 gm

Zinc 1.01 % Zn 1.25 % ZnO

Iron 16.35 % Fe 21.03 % FeO

Arsenic 23.09 % As 35.41 % As₂O₅

Hydrogen 0.28 % H 2.50 % H₂O

Lead 35.12 % Pb 37.83 % PbO

Oxygen 24.16 % O

______ ______

100.00 % 98.03 % = TOTAL OXIDE

Empirical Formula:

Pb_1.1Fe²⁺_1.9Zn_0.1(AsO₄)₂(OH)_1.8

Environment:

In an arsenic-rich reaction halo in fractures and cavities in a spessartine-quartz rock in the oxidation zone of a metamorphosed stratiform Pb-Zn orebody.

IMA Status:

Approved IMA 1989

Locality:

Kintore open cut, Broken Hill, New South Wales, Australia. Link to MinDat.org Location Data.

Name Origin:

Named for Sir Maurice Alan Edgar Mawby (1904-1977), for his contribution to the Australian mining industry.

Name Pronunciation:

Mawbyite

Synonym:

ICSD 85132

PDF 45-1468

Mawbyite Image

Images:

Mawbyite

Comments: Brown crystalline mawbyite in quartz.
Location: Kintore Open Cut, Broken Hill, New South Wales, Australia. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Mawbyite Crystallography

Axial Ratios:

a:b:c =1.4422:1:1.2033

Cell Dimensions:

a = 9.066, b = 6.286, c = 7.564, Z = 2; beta = 114.857° V = 391.13 Den(Calc)= 5.51

Crystal System:

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

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

By Intensity(I/I_o): 3.245(1), 4.647(1), 2.724(0.7),

Physical Properties of Mawbyite

Cleavage:

{001} Good

Color:

Light brown, Reddish brown, Pale orange, Orange brown.

Density:

5.5

Diaphaneity:

Transparent to Translucent

Fracture:

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

Habit:

Spherical - Spherical, rounded aggregates.

Habit:

Wheat Sheaf - Bundle shaped aggregates resembling wheat sheafs after hand reaping wheat.

Hardness:

4 - Fluorite

Luster:

Adamantine

Streak:

orange

Optical Properties of Mawbyite

Gladstone-Dale:

CI meas= -0.145 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.143 (Poor) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1803,KPDmeas= 0.1806,KC= 0.1577
Ncalc = 1.87

Optical Data:

Biaxial (-), a=1.94, b=2, g=2.04, bire=0.1000, 2V(Calc)=76, 2V(Meas)=80.

Calculated Properties of Mawbyite

Electron Density:

Bulk Density (Electron Density)=4.90 gm/cc
note: Specific Gravity of Mawbyite =5.51 gm/cc.

Fermion Index:

Fermion Index = 0.08
Boson Index = 0.92

Photoelectric:

PE_Mawbyite= 628.43 barns/electron
U=PE_Mawbyite x rElectron Density=3,081.61 barns/cc.

Radioactivity:

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

Mawbyite Classification

Dana Class:

40.02.09.04 (40)Hydrated Phosphates, etc

(40.02)where A++ (B++)2 (XO4) ï¿½ x(H2O)

(40.02.09)Helmutwinklerite Subgroup

40.02.09.01 Tsumcorite PbZnFe(AsO4)2•(H2O) C 2/m 2/m

40.02.09.02 Helmutwinklerite PbZn2(AsO4)2•2(H2O) P1 1

40.02.09.03 Thometzekite Pb(Cu,Zn)2(AsO4)2•2(H2O) C 2/m 2/m

40.02.09.04 Mawbyite Pb(FeZn)2(AsO4)2(OH,H2O)2 C 2/m 2/m

40.02.09.05 Rappoldite! Pb(Co,Ni,Zn,)2(AsO4)2•2(H2O) P1 1

40.02.09.06 Schneebergite! Bi(Co,Ni)2(AsO4)2(OH,H2O)2 C 2/m 2/m

40.02.09.07 Nickelschneebergite! Bi(Ni,Co)2(AsO4)2(OH,H2O)2 C 2/m 2/m

40.02.09.08 Cobalttsumcorite! Pb(Co,Fe)2(AsO4)2(OH,H2O)2 C 2/m 2/m

Strunz Class:

08.CG.15 08 - PHOSPHATES, ARSENATES, VANADATES

08.C - Phosphates without Additional Anions, with H2O

08.CG -With large and medium-sized cations, RO4:H2O = 1:1

08.CG.15 Cobaltlotharmeyerite! Ca(Co,Fe,Ni)2(AsO4)2(OH,H2O)2 C 2/m 2/m

08.CG.15 Ferrilotharmeyerite Ca(Zn,Cu)(Fe,Zn)(AsO4)2(OH,H2O)2 C 2/m 2/m

08.CG.15 Cabalzarite! Ca(Mg,Al,Fe)2(AsO4)2(H2O,OH)2 C 2/m 2/m

08.CG.15 Mawbyite Pb(FeZn)2(AsO4)2(OH,H2O)2 C 2/m 2/m

08.CG.15 Lotharmeyerite CaZnMn(AsO3OH)4(OH)3 C 2/m,C 2,Cm Mono

08.CG.15 Mounanaite PbFe2(VO4)2(OH)2 P1 1

08.CG.15 Tsumcorite PbZnFe(AsO4)2•(H2O) C 2/m 2/m

08.CG.15 Thometzekite Pb(Cu,Zn)2(AsO4)2•2(H2O) C 2/m 2/m

08.CG.15 Cobalttsumcorite! Pb(Co,Fe)2(AsO4)2(OH,H2O)2 C 2/m 2/m

08.CG.15 Manganlotharmeyerite! Ca(Mn,Mg,)2(AsO4)2(OH,H2O)2 C 2/m 2/m

08.CG.15 Nickellotharmeyerite! Ca(Ni,Fe,Co)2(AsO4)2(OH,H2O)2 C 2/m 2/m

08.CG.15 Krettnichite! PbMn2(VO4)2(OH)2 C 2/m 2/m

08.CG.15 Schneebergite! Bi(Co,Ni)2(AsO4)2(OH,H2O)2 C 2/m 2/m

08.CG.15 Nickelschneebergite! Bi(Ni,Co)2(AsO4)2(OH,H2O)2 C 2/m 2/m

Other Mawbyite Information

References:

NAME( AntBidBlaNic4) PHYS. PROP.(Am.Min.,Vol.74,p1377-1381,1989) OPTIC PROP.(AntBidBlaNic4)

See Also:

Links to other databases for Mawbyite :
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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Mawbyite

Pb(Fe+++Zn)2(AsO4)2(OH,H2O)2
Dana No: 40.02.09.04 Strunz No: 08.CG.15
Locality:

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