Dachiardite-Na Mineral Data

General Dachiardite-Na Information

Chemical Formula:

(Na2,Ca,K2)4Al4Si20O48•13(H2O)

Composition:

Molecular Weight = 1,808.84 gm

Potassium 1.53 % K 1.85 % K₂O

Barium 0.08 % Ba 0.08 % BaO

Sodium 3.29 % Na 4.44 % Na₂O

Calcium 1.17 % Ca 1.64 % CaO

Magnesium 0.05 % Mg 0.09 % MgO

Aluminum 7.25 % Al 13.70 % Al₂O₃

Iron 0.34 % Fe 0.49 % Fe₂O₃

Silicon 30.45 % Si 65.14 % SiO₂

Hydrogen 1.50 % H 13.38 % H₂O

Oxygen 54.34 % O

______ ______

100.00 % 100.80 % = TOTAL OXIDE

Empirical Formula:

Na_2.59Ca_0.53K_0.71Mg_0.04Ba_0.01Al_4.86Fe³⁺_0.11Si_19.61O₄₈�13.43(H₂O)

Environment:

Secondary mineral hydrothermally altered from calc-alkalic to alkalic volcanic and plutonic rocks.

IMA Status:

Approved IMA 1977

Locality:

From La Pallaccia and Orli di Fassa, Alpe di Siusi, Trentoin-Alto Adige, Italy. Link to MinDat.org Location Data.

Name Origin:

Named for its relationship to dachiardite and the sodium content.

Name Pronunciation:

Dachiardite-Na + Pronunciation

Synonym:

Achiardite

Sodiumdachiardite - renamed Dachiardite-Na

Svetlozarite - twinned

Dachiardite-Na Image

Images:

Dachiardite-Na

Comments: Orange flat radial crystals of dachiardite-Na to 2cm across on matrix.
Location: Alpe di Siusi, Bolzano, Trentino Alto Adige, Italy. Scale: Specimen size: 6x4x3cm.
© Tom Loomis / Dakota Matrix

Dachiardite-Na Crystallography

Axial Ratios:

a:b:c =2.4842:1:1.3717

Cell Dimensions:

a = 18.647, b = 7.506, c = 10.296, Z = 1; beta = 108.37° V = 1,367.64 Den(Calc)= 2.20

Crystal System:

Monoclinic - Prismatic H-M Symbol (2/m) Space Group: C 2/m

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

By Intensity(I/I_o): 3.45(1), 8.88(0.8), 6.92(0.8),3.75(0.7), 4.86(0.6), 3.38(0.6), 3.2(0.6),

Physical Properties of Dachiardite-Na

Cleavage:

{1} Perfect, {1} Perfect

Color:

Colorless, White, Reddish orange.

Density:

2.16

Diaphaneity:

Transparent to translucent

Fracture:

Brittle - Uneven - Very brittle fracture producing uneven fragments.

Habit:

Acicular - Occurs as needle-like crystals.

Habit:

Bladed - Aggregates of thin lath-like crystals (e.g. kyanite).

Habit:

Divergent - Crystals radiate from a center without producing stellar forms.

Hardness:

4-5 - Fluorite-Apatite

Luster:

Vitreous - Greasy

Streak:

white

Optical Properties of Dachiardite-Na

Gladstone-Dale:

CI meas= 0.024 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= 0.041 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2173,KPDmeas= 0.2213,KC= 0.2266
Ncalc = 1.49 - 1.5

Optical Data:

Biaxial (-), a=1.471-1.48, b=1.475-1.481, g=1.476-1.485, bire=0.0050, 2V(Calc)=52-54, 2V(Meas)=52-92. Dispersion r < v moderate.

Calculated Properties of Dachiardite-Na

Electron Density:

Bulk Density (Electron Density)=2.18 gm/cc
note: Specific Gravity of Dachiardite-Na =2.16 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_{Dachiardite-Na}= 2.15 barns/electron
U=PE_{Dachiardite-Na} x r_electron= 4.70 barns/cc.

Radioactivity:

GRapi = 22.34 (Gamma Ray American Petroleum Institute Units)
Concentration of Dachiardite-Na per GRapi unit = 4.48 (%)

Estimated Radioactivity from Dachiardite-Na - barely detectable

Dachiardite-Na Classification

Dana Class:

77.01.06.05 (77)Tectosilicate Zeolite group

(77.01)true zeolites

(77.01.06)Mordenite and related species

77.01.06.01 Mordenite (Ca,Na2,K2)Al2Si10O24•7(H2O) C mc2₁ mm2

77.01.06.02 Epistilbite CaAl2Si6O16•5(H2O) C1 1

77.01.06.03 Maricopaite Pb7Ca2(Si,Al)48O100•32(H2O) Cm2m 2/m 2/m 2/m

77.01.06.04 Dachiardite-Ca (Ca,Na2,K2)5Al10Si38O96•25(H2O) C 2/m 2/m

77.01.06.05 Dachiardite-Na (Na2,Ca,K2)4Al4Si20O48•13(H2O) C 2/m 2/m

77.01.06.06 Ferrierite-Mg (Mg,Na,K)2Mg(Si,Al)18O36•9(H2O) Pnnm 2/m 2/m 2/m

77.01.06.06a Ferrierite-K! (K,Na)2Mg(Si,Al)18O36•9(H2O) Pnnm 2/m 2/m 2/m

77.01.06.06b Ferrierite-Na! (Na,K)2Mg(Si,Al)18O36•9(H2O) P 2₁/n 2/m

77.01.06.07 Boggsite NaCa2(Al5Si19O48)•17(H2O) I mma 2/m 2/m 2/m

77.01.06.08 Gottardiite! Na3Mg3Ca5Al19Si117O272•93(H2O) C mca 2/m 2/m 2/m

77.01.06.09 Terranovaite! (Na,Ca)8(Si68Al12)O160•29(H2O) C mcm 2/m 2/m 2/m

77.01.06.10 Mutinaite! Na3Ca4Si85Al11O192•60(H2O) P nma 2/m 2/m 2/m

77.01.06.12 Direnzoite! NaK6MgCa2(Al13Si47O120)•36H2O Pmmn 2/m 2/m 2/m

Strunz Class:

09.GD.40 09 - SILICATES (Germanates)

09.G - Tektosilicates with Zeolitic H2O

09.GD -Chains of 6-membered rings � tabular zeolites

09.GD.40 Dachiardite-Ca (Ca,Na2,K2)5Al10Si38O96•25(H2O) C 2/m 2/m

09.GD.40 Dachiardite-Na (Na2,Ca,K2)4Al4Si20O48•13(H2O) C 2/m 2/m

Other Dachiardite-Na Information

References:

NAME( AntBidBlaNic2) PHYS. PROP.(AntBidBlaNic2, CanMin, v 35, p 1580) OPTIC PROP.(AntBidBlaNic2)

See Also:

Links to other databases for Dachiardite-Na :
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

Search for Dachiardite-Na using:

[AOL] [Bing] [Dog Pile] [GeoScienceWorld] [HotBot] [Ixquick] [Lycos] [MAMMA] [Scirus] [Teoma] [WebCrawler] [Wikipedia] [YAHOO]

Visit our Advertisers for Dachiardite-Na :

Ask about Dachiardite-Na 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 Espa�ol

Print or Cut-and-Paste your Dachiardite-Na Specimen Label here :

Dachiardite-Na

(Na2,Ca,K2)4Al4Si20O48•13(H2O)
Dana No: 77.01.06.05 Strunz No: 09.GD.40
Locality:

Notes:

Dakota Matrix
Excalibur Minerals
Exceptional Minerals
Hudson Insitute
John Betts Fine Minerals
Mc Dougall Minerals
Mineral News
Rock and Mineral Shows
Weinrich Minerals, Inc.