Silvialite Mineral Data

Silvialite Mineral Data

General Silvialite Information

Chemical Formula:

(Ca,Na)4Al6Si6O24(SO4,CO3)

Composition:

Molecular Weight = 939.25 gm

Sodium 2.45 % Na 3.30 % Na₂O

Calcium 12.80 % Ca 17.91 % CaO

Aluminum 17.24 % Al 32.57 % Al₂O₃

Silicon 17.94 % Si 38.38 % SiO₂

Carbon 0.51 % C 1.87 % CO₂

Sulfur 2.05 % S 5.11 % SO₃

Oxygen 47.01 % O

______ ______

100.00 % 99.15 % = TOTAL OXIDE

Empirical Formula:

Ca₃NaAl₆Si₆O₂₄(SO₄)_0.6(CO₃)_0.4

Environment:

Garnet-granulite mantle-derived xenolith in olivine nephelinite. A member of the scapolite group.

IMA Status:

Approved IMA 1999 (Dana # Added)

Locality:

McBride Province, North Queensland, Australia. Link to MinDat.org Location Data.

Name Origin:

Named for Silvia Hillebrand, daughter of G. Tschermak, was first suggested in 1914 for the then-hypothetical SO4 analog of meionite.

Synonym:

ICSD 88935

IMA1998-010

Search for Silvialite Images

Images:

Image not yet available on Webmineral.com

Try searching images.google.com or Mindat Picture Gallary for mineral pictures. Caution: The images retrieved may not be appropriate.

Silvialite Crystallography

Axial Ratios:

a:c = 1:0.62436

Cell Dimensions:

a = 12.134, c = 7.576, Z = 2; V = 1,115.44 Den(Calc)= 2.80

Crystal System:

Tetragonal - DipyramidalH-M Symbol (4/m) Space Group: I 4/m

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

By Intensity(I/I_o): 3.45(1), 3.07(0.4), 3.82(0.2),2.69(0.15), 3.04(0.15),

Physical Properties of Silvialite

Cleavage:

[100] Good

Color:

Slightly yellowish white, Colorless.

Density:

2.75

Diaphaniety:

Transparent

Fracture:

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

Habit:

Granular - Generally occurs as anhedral to subhedral crystals in matrix.

Habit:

Subhedral Crystals - Occurs as crystals which tend to exhibit a recognizable crystal shape.

Hardness:

5.5 - Knife Blade

Luster:

Vitreous (Glassy)

Streak:

white

Optical Properties of Silvialite

Gladstone-Dale:

CI meas= -0.018 (Superior) - where the CI = (1-KPDmeas/KC)
CI calc= 0 (Superior) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2041,KPDmeas= 0.2078,KC= 0.2041

Optical Data:

Uniaxial (-), e=1.558, w=1.585, bire=0.0270.

Calculated Properties of Silvialite

Electron Density:

r_electron=2.78 gm/cc
note: r_Silvialite=2.80 gm/cc.

Fermion Index

Fermion Index = 0.00898
Boson Index = 0.99102

Photoelectric:

PE_Silvialite= 2.94 barns/electron
U=PE_Silvialite x r_electron= 8.17 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)

Silvialite is Not Radioactive

Silvialite Classification

Dana Class:

76.3.1.3 (76)Tectosilicate Al-Si Framework

(76.3)with other Be/Al/Si frameworks

(76.3.1)Scapolite group

76.3.1.0 Scapolite* (Na,Ca)4[Al3Si9O24]Cl P 4₁/n 4/m

76.3.1.1 Marialite Na4Al3Si9O24Cl I 4/m 4/m

76.3.1.2 Meionite Ca4Al6Si6O24CO3 P 4/m 4/m

76.3.1.3 Silvialite ! (Ca,Na)4Al6Si6O24(SO4,CO3) I 4/m 4/m

Strunz Class:

VIII/J.13-25 VIII - Silicates

VIII/J - Tectosilicates (network) with anions unfamiliar to the tetraheders

VIII/J.13 - Sodalite group, Marialite - Kalborsite series

VIII/J.13-10 Marialite Na4Al3Si9O24Cl I 4/m 4/m

VIII/J.13-20 Meionite Ca4Al6Si6O24CO3 P 4/m 4/m

VIII/J.13-25 Silvialite (Ca,Na)4Al6Si6O24(SO4,CO3) I 4/m 4/m

VIII/J.13-30 Sarcolite NaCa6Al4Si6O24F(?) I 4/m 4/m

VIII/J.13-40 Kalborsite K6Al4Si6BO20(OH)4Cl P 42m 4 2m

Other Silvialite Information

References:

NAME( AmMin, V85, p264) PHYS. PROP.(AmMin, V85, p264) OPTIC PROP.(AmMin, V85, p264)

See Also:

Links to other databases for Silvialite :
1 -Am. Min. Crystal Structure Database 2 -Athena 3 - Crocoite.com Mineral Locations 4 -Google Images 5 -Google Scholar 6 -MinDAT 7 -MinMax(Deutsch) 8 -MinMax(English) 9 -Mineralienatlas (Deutsch) 10 -QUT Mineral Atlas

Search for Silvialite using:

[ALTAVISTA] [AOL] [About.com] [All-The-Web] [HotBot] [Ixquick] [LookSmart] [MAMMA] [MSN.COM] [Netscape] [Teoma] [Wikipedia] [YAHOO]

Visit our Advertisers for Silvialite :
AA Mineral Specimens
A-Rocks Auction
Adams Minerals
B and L Minerals
Dakota Matrix
Dan Weinrich Fine Minerals
Dan Weinrich Auctions
e-Rocks Auctions
Excalibur Minerals
Exceptional Minerals
Fabre Minerals
Greenside Minerals
John Betts Fine Minerals
Masons Minerals
Mineral News
Mineral of the Month Club
MineralsWeb Fine Minerals
Minernet.it
Rockshop.cz Kalat Fine Minerals
T G Fine Minerals
Wrights Rock Shop

Translate Silvialite Mineral Data :

Ask about Silvialite here :
Ask-A-Mineralogist from the Mineralogical Society of America
Mindat.org's Discussion Groups
Original Rockhounds Discussion Group
Rockhounds Discussion Group on Yahoo Groups
Mineral Discussion Forum from Fabre Minerals - also available in Español

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

Silvialite

(Ca,Na)4Al6Si6O24(SO4,CO3)
Dana No: 76.3.1.3 Strunz No: VIII/J.13-25
Locality:

Notes: