Darapskite Mineral Data

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General Darapskite Information

Chemical Formula:

Na3(SO4)(NO3)•(H2O)

Composition:

Molecular Weight = 245.05 gm

Sodium 28.14 % Na 37.94 % Na₂O

Hydrogen 0.82 % H 7.35 % H₂O

Sulfur 13.09 % S 32.67 % SO₃

Nitrogen 5.72 % N 22.04 % N₂O₅

Oxygen 52.23 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₃(SO₄)(NO₃)•(H₂O)

Environment:

Found in nitrate deposits, filling veins and cavities in cemented regolith, in an arid region.

IMA Status:

Valid Species (Pre-IMA) 1891

Locality:

Antofagasta, from Oficina Lautaro, Pampa del Toro, Taltal district, Chile. Link to MinDat.org Location Data.

Name Origin:

Named for Ludwig Darapsky (1857-1916), German-Chilean chemist and mineralogist, Santiago, Chile.

Name Pronunciation:

Darapskite + Pronunciation

Synonym:

ICSD 26927

PDF 23-1408

Darapskite Image

Images:

Darapskite

Comments: White crystalline granular darapskite.
Location: Iquique, Tarapaca, Chile. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Darapskite Crystallography

Axial Ratios:

a:b:c =1.5281:1:0.7506

Cell Dimensions:

a = 10.564, b = 6.913, c = 5.189, Z = 2; beta = 102.77° V = 369.57 Den(Calc)= 2.20

Crystal System:

Monoclinic - PrismaticH-M Symbol (2/m) Space Group: P 2₁/m

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

By Intensity(I/I_o): 10.29(1), 2.865(0.35), 3.456(0.35),

Forms:

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

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Crystal Structure:

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Sabelli C , Atti della Accademia Nazionale dei Lincei , 42 (1967) p.874-887, La struttura della darapskite

Physical Properties of Darapskite

Cleavage:

{100} Perfect, {010} Good

Color:

Colorless.

Density:

2.202

Diaphaneity:

Transparent to Translucent

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Hardness:

2.5 - Finger Nail

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Darapskite

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= 0.205,KPDmeas= 0.2048,KC= 0.2082
Ncalc = 1.46

Optical Data:

Biaxial (-), a=1.388, b=1.479, g=1.486, bire=0.0980, 2V(Calc)=28, 2V(Meas)=27.

Calculated Properties of Darapskite

Electron Density:

Bulk Density (Electron Density)=2.19 gm/cc
note: Specific Gravity of Darapskite =2.20 gm/cc.

Fermion Index:

Fermion Index = 0.05
Boson Index = 0.95

Photoelectric:

PE_Darapskite= 1.34 barns/electron
U=PE_Darapskite x rElectron Density= 2.93 barns/cc.

Radioactivity:

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

Darapskite Classification

Dana Class:

20.01.01.01 (20)Compound Nitrates

(20.01)with other anions

(20.01.01)Dana Group

20.01.01.01 Darapskite Na3(SO4)(NO3)•(H2O) P 2₁/m 2/m

Strunz Class:

07.DG.05 07 - SULFATES (SELENATES, TELLURATES)

07.D - Sulfates (selenates, etc.) with additional anions, with H2O

07.DG -With large and medium sized cations; with NO3, CO3, B(OH)4, SiO4 or IO3

07.DG.05 Darapskite Na3(SO4)(NO3)•(H2O) P 2₁/m 2/m

Other Darapskite Information

References:

NAME( AntBidBlaNic3) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Darapskite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - EUROmin Project
4 - Ecole des Mines de Paris
5 - Google Images
6 - Google Scholar
7 - Handbook of Mineralogy (MinSocAm)
8 - Handbook of Mineralogy (UofA)
9 - MinDAT
10 - MinMax(Deutsch)
11 - MinMax(English)
12 - Mineralienatlas (Deutsch)
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - WWW-MINCRYST

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

Darapskite

Na3(SO4)(NO3)•(H2O)
Dana No: 20.01.01.01 Strunz No: 07.DG.05
Locality:

Notes: