Sarmientite Mineral Data

General Sarmientite Information

Chemical Formula:

Fe+++2(AsO4)(SO4)(OH)•5(H2O)

Composition:

Molecular Weight = 453.76 gm

Iron 24.62 % Fe 35.19 % Fe₂O₃

Arsenic 16.51 % As 25.33 % As₂O₅

Hydrogen 2.44 % H 21.84 % H₂O

Sulfur 7.07 % S 17.64 % SO₃

Oxygen 49.36 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Fe³⁺₂(AsO₄)(SO₄)(OH)•5(H₂O)

Environment:

Rare mineral in oxidized pyritic veins in diabase.

IMA Status:

Valid Species (Pre-IMA) 1941

Locality:

Santa Elena mine, Quebrada de La Alcaparrosa, between San Juan and Calingasta, San Juan Province, Argentina. Link to MinDat.org Location Data.

Name Origin:

Named for Domingo Faustino Sarmiento (1811-1888), former President of Argentina.

Sarmientite Image

Images:

Sarmientite

Comments: Pale olive-green chalky massive sarmientite.
Location: Kotzebue, Alaska, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Sarmientite Crystallography

Axial Ratios:

a:b:c =0.353:1:0.5229

Cell Dimensions:

a = 6.55, b = 18.55, c = 9.7, Z = 4; beta = 97.65° V = 1,168.08 Den(Calc)= 2.58

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): 9.29(1), 4.64(0.9), 4.26(0.8),

Physical Properties of Sarmientite

Color:

Yellow orange, Light yellow, Light orange.

Density:

2.58

Streak:

white

Optical Properties of Sarmientite

Gladstone-Dale:

CI meas= 0.016 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0.016 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2534,KPDmeas= 0.2534,KC= 0.2574
Ncalc = 1.66

Optical Data:

Biaxial (+), a=1.628, b=1.635, g=1.698, bire=0.0700, 2V(Calc)=38, 2V(Meas)=38.

Calculated Properties of Sarmientite

Electron Density:

Bulk Density (Electron Density)=2.55 gm/cc
note: Specific Gravity of Sarmientite =2.58 gm/cc.

Fermion Index:

Fermion Index = 0.005989033
Boson Index = 0.994010967

Photoelectric:

PE_Sarmientite= 18.60 barns/electron
U=PE_Sarmientite x rElectron Density= 47.38 barns/cc.

Radioactivity:

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

Sarmientite Classification

Dana Class:

43.05.01.01 (43)Compound Phosphates, etc.

(43.05)(Hydrated Compound Anions With Hydroxyl or Halogen)

(43.05.01)Sarmientite Group

43.05.01.01 Sarmientite Fe2(AsO4)(SO4)(OH)•5(H2O) P 2₁/c 2/m

43.05.01.02 Bukovskyite Fe2(AsO4)(SO4)(OH)•7(H2O) P1 or P1 Tri

43.05.01.03 Sanjuanite Al2(PO4)(SO4)(OH)•9(H2O) P1 or P1 Tri

Strunz Class:

08.DB.35 08 - PHOSPHATES, ARSENATES, VANADATES

08.D - Phosphates, etc

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

08.DB.35 Sarmientite Fe2(AsO4)(SO4)(OH)•5(H2O) P 2₁/c 2/m

Other Sarmientite 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 Sarmientite :
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 Sarmientite Specimen Label here :

Sarmientite

Fe+++2(AsO4)(SO4)(OH)•5(H2O)
Dana No: 43.05.01.01 Strunz No: 08.DB.35
Locality:

Notes:

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