Mcnearite Mineral Data

General Mcnearite Information

Chemical Formula:

NaCa5H4(AsO4)5•4(H2O)

Composition:

Molecular Weight = 994.07 gm

Sodium 2.31 % Na 3.12 % Na₂O

Calcium 20.16 % Ca 28.21 % CaO

Arsenic 37.68 % As 57.80 % As₂O₅

Hydrogen 1.22 % H 10.87 % H₂O

Oxygen 38.63 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

NaCa₅H₄(AsO₄)₅•4(H₂O)

IMA Status:

Approved IMA 1981

Locality:

Ste.-Marie-aux-Mines, Vosges Mountains, Alsace, France. Link to MinDat.org Location Data.

Name Origin:

Named for Elizabeth McNear, mineralogist and crystallographer, University of Geneva, Switzerland.

Name Pronunciation:

Mcnearite + Pronunciation

Mcnearite Image

Images:

Mcnearite

Comments: Crystalline mcnearite micro botryoids on matrix.
Location: Gabbe Gottes, Sainte-Marie-aux-Mines, Haute-Rhin, France. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Mcnearite Crystallography

Axial Ratios:

a:b:c =0.9574:1:0.4929

Cell Dimensions:

a = 13.5, b = 14.1, c = 6.95, Z = 2; alpha = 90°, beta = 92°, gamma = 119° V = 1,156.36 Den(Calc)= 2.85

Crystal System:

Triclinic Space Group: P1,P 1

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

By Intensity(I/I_o): 12.33(1), 3.122(0.6), 3.92(0.6),

Physical Properties of Mcnearite

Cleavage:

{???} Perfect

Color:

White.

Density:

2.6

Habit:

Fibrous - Crystals made up of fibers.

Habit:

Radial - Crystals radiate from a center without producing stellar forms (e.g. stibnite)

Luster:

Pearly

Streak:

white

Optical Properties of Mcnearite

Gladstone-Dale:

CI meas= -0.109 (Poor) - where the CI = (1-KPDmeas/KC)
CI calc= -0.008 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.1973,KPDmeas= 0.2171,KC= 0.1958
Ncalc = 1.51 - 1.56

Optical Data:

Biaxial (+), a=1.559, b=1.562, g=1.572, bire=0.0130, 2V(Calc)=58, 2V(Meas)=60.

Calculated Properties of Mcnearite

Electron Density:

Bulk Density (Electron Density)=2.76 gm/cc
note: Specific Gravity of Mcnearite =2.86 gm/cc.

Fermion Index:

Fermion Index = 0.0004593786
Boson Index = 0.9995406214

Photoelectric:

PE_Mcnearite= 27.89 barns/electron
U=PE_Mcnearite x rElectron Density= 77.04 barns/cc.

Radioactivity:

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

Mcnearite Classification

Dana Class:

39.03.07.01 (39)Hydrated Acid Phosphates, etc

(39.03)with miscellaneous formulae

(39.03.07)Dana Group

39.03.07.01 Mcnearite NaCa5H4(AsO4)5•4(H2O) P1,P 1 Tri

Strunz Class:

08.CJ.55 08 - PHOSPHATES, ARSENATES, VANADATES

08.C - Phosphates without Additional Anions, with H2O

08.CJ -With only large cations

08.CJ.55 Mcnearite NaCa5H4(AsO4)5•4(H2O) P1,P 1 Tri

Other Mcnearite Information

References:

NAME( Dana8) PHYS. PROP.(Dana8) OPTIC PROP.(Dana8)

See Also:

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

Mcnearite

NaCa5H4(AsO4)5•4(H2O)
Dana No: 39.03.07.01 Strunz No: 08.CJ.55
Locality:

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