Rivadavite Mineral Data

Rivadavite Mineral Data +

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General Rivadavite Information

Chemical Formula:

Na6MgB24O40·22(H2O)

Composition:

Molecular Weight = 1,458.00 gm

Sodium 9.46 % Na 12.75 % Na₂O

Magnesium 1.67 % Mg 2.76 % MgO

Boron 17.79 % B 57.30 % B₂O₃

Hydrogen 3.04 % H 27.18 % H₂O

Oxygen 68.04 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

Na₆MgB₂₄O₄₀·22(H₂O)

IMA Status:

Approved IMA 1967

Locality:

Link to MinDat.org Location Data.

Synonym:

ICSD 31455

PDF 19-1211

Rivadavite Image

Images:

Rivadavite

Comments: Translucent white rivadavite nodule with some adhering earthy material.
Location: Tincalayu, Salta Province, Argentina. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Rivadavite Crystallography

Axial Ratios:

a:b:c =1.845:1:1.3892

Cell Dimensions:

a = 14.779, b = 8.01, c = 11.128, Z = 1; beta = 105.9° V = 1,266.93 Den(Calc)= 1.91

Crystal System:

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

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

By Intensity(I/I_o): 7.59(1), 14.2(1), 2.95(0.66),

Physical Properties of Rivadavite

Cleavage:

[100] Perfect, [101] Perfect, [010] Indistinct

Color:

Colorless, White.

Density:

1.905

Diaphaniety:

Transparent

Fracture:

Brittle - Generally displayed by glasses and most non-metallic minerals.

Hardness:

3.5 - Copper Penny

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Rivadavite

Gladstone-Dale:

CI meas= -0.033 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.03 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2527,KPDmeas= 0.2534,KC= 0.2454

Optical Data:

Biaxial (+), a=1.47, b=1.481, g=1.497, bire=0.0270, 2V(Calc)=82, 2V(Meas)=80.

Calculated Properties of Rivadavite

Electron Density:

r_electron=1.93 gm/cc
note: r_Rivadavite=1.91 gm/cc.

Fermion Index

Fermion Index = 0.0374
Boson Index = 0.9626

Photoelectric:

PE_Rivadavite= 0.47 barns/electron
U=PE_Rivadavite x r_electron= 0.91 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Rivadavite is Not Radioactive

Rivadavite Classification

Dana Class:

26.6.1.1 (26)Hydrated Borates Containing Hydroxyl or Halogen

(26.6)Dana Type

(26.6.1)Dana Group

26.6.1.1 Rivadavite Na6MgB24O40·22(H2O) P 2₁/c 2/m

Strunz Class:

V/H.17-40 V - Nitrates, Carbonates and Borates

V/H - Group borates. Planary and tetrahedral groups [B3O5]1- to [B6O10]2-

V/H.17 - Admontite - Rivadavite series

V/H.17-10 Admontite MgB6O10·7(H2O) P 2₁/c 2/m

V/H.17-20 Mcallisterite Mg2B12O14(OH)12·9(H2O) R 3c 3 2/m

V/H.17-30 Aksaite MgB6O7(OH)6·2(H2O) P bca 2/m 2/m 2/m

V/H.17-40 Rivadavite Na6MgB24O40·22(H2O) P 2₁/c 2/m

Other Rivadavite Information

References:

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

See Also:

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

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

Rivadavite

Na6MgB24O40·22(H2O)
Dana No: 26.6.1.1 Strunz No: V/H.17-40
Locality:

Notes: