Chiavennite Mineral Data

General Chiavennite Information

Chemical Formula:

CaMnBe2Si5O13(OH)2•2(H2O)

Composition:

Molecular Weight = 531.51 gm

Calcium 7.54 % Ca 10.55 % CaO

Manganese 10.34 % Mn 13.35 % MnO

Beryllium 3.39 % Be 9.41 % BeO

Silicon 26.42 % Si 56.52 % SiO₂

Hydrogen 1.14 % H 10.17 % H₂O

Oxygen 51.17 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

CaMn²⁺Be₂Si₅O₁₃(OH)₂•2(H₂O)

Environment:

Coating beryl in late-stage pegmatites (Tanno, Italy); in vugs in syenite pegmatites (Norway).

IMA Status:

Approved IMA 1983

Locality:

From Tanno, Chiavenna, Lombardy, Italy. Link to MinDat.org Location Data.

Name Origin:

Named for the locality.

Synonym:

ICSD 80917

PDF 35-602

Chiavennite Image

Images:

Chiavennite

Comments: Prismatic micro crystals of chiavennite less than 1mm.
Location: Ute, Sweden. Scale: Picture size 1 cm.
© Tom Loomis / Dakota Matrix

Chiavennite Crystallography

Axial Ratios:

a:b:c =0.2786:1:0.1565

Cell Dimensions:

a = 8.729, b = 31.326, c = 4.903, Z = 4; V = 1,340.70 Den(Calc)= 2.63

Crystal System:

Orthorhombic - Dipyramidal H-M Symbol (2/m 2/m 2/m) Space Group: Pnab

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

By Intensity(I/I_o): 2.903(1), 15.7(1), 3.28(0.75),

Physical Properties of Chiavennite

Cleavage:

{???} Perfect

Color:

Yellow, Orange, Red orange.

Density:

2.64

Diaphaneity:

Translucent

Hardness:

3 - Calcite

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Chiavennite

Gladstone-Dale:

CI meas= -0.026 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.03 (Excellent) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2299,KPDmeas= 0.229,KC= 0.2232
Ncalc = 1.59

Optical Data:

Biaxial (+), a=1.596, b=1.6, g=1.618, bire=0.0220, 2V(Calc)=52, 2V(Meas)=50.

Calculated Properties of Chiavennite

Electron Density:

Bulk Density (Electron Density)=2.63 gm/cc
note: Specific Gravity of Chiavennite =2.64 gm/cc.

Fermion Index:

Fermion Index = 0.04
Boson Index = 0.96

Photoelectric:

PE_Chiavennite= 4.57 barns/electron
U=PE_Chiavennite x rElectron Density= 12.02 barns/cc.

Radioactivity:

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

Chiavennite Classification

Dana Class:

70.05.01.01 (70)Inosilicate Column or Tube Structures

(70.05)with chains linked by Be

(70.05.01)Dana Group

70.05.01.01 Chiavennite CaMnBe2Si5O13(OH)2•2(H2O) Pnab 2/m 2/m 2/m

Strunz Class:

09.GF.25 09 - SILICATES (Germanates)

09.G - Tektosilicates with Zeolitic H2O

09.GF -Other Rare Zeolites

09.GF.25 Chiavennite CaMnBe2Si5O13(OH)2•2(H2O) Pnab 2/m 2/m 2/m

Other Chiavennite Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Chiavennite :
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
16 - Zeolite Database by Bruno Herreros

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Chiavennite

CaMnBe2Si5O13(OH)2•2(H2O)
Dana No: 70.05.01.01 Strunz No: 09.GF.25
Locality:

Notes:

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