Durangite Mineral Data

General Durangite Information

Chemical Formula:

NaAl(AsO4)F

Composition:

Molecular Weight = 207.89 gm

Sodium 11.06 % Na 14.91 % Na₂O

Aluminum 12.98 % Al 24.52 % Al₂O₃

Arsenic 36.04 % As 55.28 % As₂O₅

Oxygen 30.78 % O

Fluorine 9.14 % F 9.14 % F

- % F -3.85 % -O=F₂

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

NaAl(AsO₄)F

Environment:

Veins in alkalic rhyolite and tin placers derived therefrom. Forms two series, with maxwellite and with tilasite.

IMA Status:

Valid Species (Pre-IMA) 1869

Locality:

Barranca tin mine, about 30 km northeast of Coneto de Comonfort, Durango, Mexico. Link to MinDat.org Location Data.

Name Origin:

Named for th locality.

Name Pronunciation:

Durangite + Pronunciation

Synonym:

ICSD 30205

PDF 36-424

Durangite Image

Images:

Durangite

Comments: Equant red crystals of durangite with a dusting of white powder.
Location: Northern end Thomas Range, Juab County, Utah, USA. Scale: See Image.
© Rruff Database

Durangite Crystallography

Axial Ratios:

a:b:c =0.7719:1:0.8269

Cell Dimensions:

a = 6.579, b = 8.523, c = 7.048, Z = 4; beta = 115.47° V = 356.79 Den(Calc)= 3.87

Crystal System:

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

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Forms: ( 0 2 1) ( 1 1 1) ( 0 1 0) ( 1 1 1) ( 1 1 2) ( 1 1 0) ( 1 0 0)

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Physical Properties of Durangite

Cleavage:

{???} Indistinct, {110} Distinct

Color:

Light yellow, Dark green, Orange red, Red.

Density:

3.9

Diaphaneity:

Translucent

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Hardness:

5.5 - Knife Blade

Luster:

Vitreous (Glassy)

Streak:

yellow

Optical Properties of Durangite

Gladstone-Dale:

CI meas= 0.015 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.008 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1716,KPDmeas= 0.1703,KC= 0.1729
Ncalc = 1.67

Optical Data:

Biaxial (-), a=1.634, b=1.673, g=1.685, bire=0.0510, 2V(Calc)=56, 2V(Meas)=45.

Calculated Properties of Durangite

Electron Density:

Bulk Density (Electron Density)=3.65 gm/cc
note: Specific Gravity of Durangite =3.87 gm/cc.

Fermion Index:

Fermion Index = 0.0001477657
Boson Index = 0.9998522343

Photoelectric:

PE_Durangite= 25.36 barns/electron
U=PE_Durangite x rElectron Density= 92.53 barns/cc.

Radioactivity:

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

Durangite Classification

Dana Class:

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

(41.05)where (A B)2 (XO4) Zq

(41.05.05)Lacroixite Group

41.05.05.01 Lacroixite NaAl(PO4)F C 2/c 2/m

41.05.05.02 Durangite NaAl(AsO4)F C 2/c 2/m

41.05.05.03 Maxwellite NaFe(AsO4)F Aa,A2/a Mono

Strunz Class:

08.BH.10 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.10 Durangite NaAl(AsO4)F C 2/c 2/m

08.BH.10 Isokite CaMg(PO4)F C 2/c 2/m

08.BH.10 Lacroixite NaAl(PO4)F C 2/c 2/m

08.BH.10 Maxwellite NaFe(AsO4)F Aa,A2/a Mono

08.BH.10 Panasqueiraite CaMg(PO4)(OH,F) C 2/c 2/m

08.BH.10 Tilasite CaMg(AsO4)F C 2/c 2/m

Other Durangite Information

References:

NAME( AntBidBlaNic4) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Durangite :
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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Durangite

NaAl(AsO4)F
Dana No: 41.05.05.02 Strunz No: 08.BH.10
Locality:

Notes:

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