Stoppaniite Mineral Data

General Stoppaniite Information

Chemical Formula:

(Fe,Al,Mg)4(Na,[ ])2[Be6Si12O36]•2(H2O)

Composition:

Molecular Weight = 1,190.23 gm

Sodium 1.82 % Na 2.45 % Na₂O

Magnesium 1.37 % Mg 2.27 % MgO

Beryllium 4.54 % Be 12.61 % BeO

Aluminum 1.75 % Al 3.30 % Al₂O₃

Iron 10.79 % Fe 13.88 % FeO

Silicon 28.32 % Si 60.58 % SiO₂

Hydrogen 0.34 % H 3.03 % H₂O

Oxygen 51.08 % O

______ ______

100.00 % 98.11 % = TOTAL OXIDE

Empirical Formula:

Fe²⁺_2.3Al_0.77Mg_0.67Na_0.94Be₆Si₁₂O₃₆•2(H₂O)

Environment:

Miarolitic cavities of a volcanic ejectum. The Fe+++ dominant analog of beryl.

IMA Status:

Approved IMA 1996 (Dana # Added)

Locality:

Capranica (Viterbo), Vico volcanic complex, Latium, Italy. Link to MinDat.org Location Data.

Name Origin:

Named for the mineral collector Francesco Saverio Stoppani (1947-).

Synonym:

ICSD 85697

IMA1996-008

PDF 83-1024

Stoppaniite Crystallography

Axial Ratios:

a:c = 1:0.98576

Cell Dimensions:

a = 9.346, c = 9.213, Z = 1; V = 696.92 Den(Calc)= 2.84

Crystal System:

Hexagonal - Dihexagonal Dipyramidal H-M Symbol (6/m 2/m 2/m) Space Group: P 6/mmc

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

By Intensity(I/I_o): 3.278(1)(112), 8.12(0.65)(010), 2.903(0.64)(121),4(0.38)(012), 1.752(0.3)(034), 2.553(0.3)(122),

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Physical Properties of Stoppaniite

Cleavage:

{0001} Parting

Color:

Light blue.

Density:

2.79

Diaphaneity:

Transparent

Fracture:

Brittle - Conchoidal - Very brittle fracture producing small, conchoidal fragments.

Habit:

Euhedral Crystals - Occurs as well-formed crystals showing good external form.

Habit:

Prismatic - Crystals Shaped like Slender Prisms (e.g. tourmaline).

Hardness:

7.5 - Garnet

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Stoppaniite

Gladstone-Dale:

CI meas= -0.068 (Fair) - where the CI = (1-KPDmeas/KC)
CI calc= -0.05 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.219,KPDmeas= 0.2229,KC= 0.2087
Ncalc = 1.58 - 1.59

Optical Data:

Uniaxial (-), e=1.619, w=1.625, bire=0.0060.

Calculated Properties of Stoppaniite

Electron Density:

Bulk Density (Electron Density)=2.81 gm/cc
note: Specific Gravity of Stoppaniite =2.84 gm/cc.

Fermion Index:

Fermion Index = 0.06
Boson Index = 0.94

Photoelectric:

PE_Stoppaniite= 4.44 barns/electron
U=PE_Stoppaniite x rElectron Density= 12.45 barns/cc.

Radioactivity:

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

Stoppaniite Classification

Dana Class:

61.01.01.04 (61)Cyclosilicate Six-Membered Rings

(61.01)with [Si6O18] rings; possible (OH) and Al substitution

(61.01.01)Beryl group

61.01.01.01 Beryl Be3Al2Si6O18 P 6/mmc 6/m 2/m 2/m

61.01.01.02 Bazzite Be3(Sc,Al)2Si6O18 P 6/mcc 6/m 2/m 2/m

61.01.01.03 Indialite Mg2Al4Si5O18 P 6/mcc 6/m 2/m 2/m

61.01.01.04 Stoppaniite! (Fe,Al,Mg)4(Na,[])2[Be6Si12O36]•2(H2O) P 6/mmc 6/m 2/m 2/m

61.01.01.05 Pezzottaite! Cs(Be2Li)Al2Si6O18 R 3c 3m

Strunz Class:

09.CJ.05 09 - SILICATES (Germanates)

09.C - Cyclosilicates

09.CJ -[Si6O18]12- 6-membered single rings (sechser-Einfachringe),

09.CJ.05 Beryl Be3Al2Si6O18 P 6/mmc 6/m 2/m 2/m

09.CJ.05 Bazzite Be3(Sc,Al)2Si6O18 P 6/mcc 6/m 2/m 2/m

09.CJ.05 Indialite Mg2Al4Si5O18 P 6/mcc 6/m 2/m 2/m

09.CJ.05 Stoppaniite! (Fe,Al,Mg)4(Na,[])2[Be6Si12O36]•2(H2O) P 6/mmc 6/m 2/m 2/m

09.CJ.05 Pezzottaite! Cs(Be2Li)Al2Si6O18 R 3c 3m

Other Stoppaniite Information

References:

NAME( AmMin, Vol 85, p 1845) PHYS. PROP.(AmMin, Vol 85, p 1845) OPTIC PROP.(Eur.J.Min.,Vol.10,p491-496,1998)

See Also:

Links to other databases for Stoppaniite :
1 - Am. Min. Crystal Structure Database
2 - Athena
3 - GeoScienceWorld
4 - Google Images
5 - Google Scholar
6 - MinDAT
7 - Mineralienatlas (Deutsch)
8 - Online Mineral Museum
9 - QUT Mineral Atlas
10 - Ruff.Info
11 - WWW-MINCRYST

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Stoppaniite

(Fe,Al,Mg)4(Na,[ ])2[Be6Si12O36]•2(H2O)
Dana No: 61.01.01.04 Strunz No: 09.CJ.05
Locality:

Notes:

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