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 % K2 O
Barium 0.08 % Ba 0.08 % BaO
Sodium 3.29 % Na 4.44 % Na2 O
Calcium 1.17 % Ca 1.64 % CaO
Magnesium 0.05 % Mg 0.09 % MgO
Aluminum 7.25 % Al 13.70 % Al2 O3
Iron 0.34 % Fe 0.49 % Fe2 O3
Silicon 30.45 % Si 65.14 % SiO2
Hydrogen 1.50 % H 13.38 % H2 O
Oxygen 54.34 % O
______ ______
100.00 % 100.80 % = TOTAL OXIDE
Empirical Formula:
Na2.59 Ca0.53 K0.71 Mg0.04 Ba0.01 Al4.86 Fe3+ 0.11 Si19.61 O48 �13.43(H2 O)
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
X Ray Diffraction:
By Intensity(I/Io ): 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:
PEDachiardite-Na = 2.15 barns/electronU=PEDachiardite-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
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Dachiardite-Na
(Na2,Ca,K2)4Al4Si20O48•13(H2O)
Dana No: 77.01.06.05 Strunz No: 09.GD.40
Locality:
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