Ashcroftine-(Y) Mineral Data

General Ashcroftine-(Y) Information

Chemical Formula:

K5Na5(Y,Ca)12Si28O70(OH)2(CO3)8•8(H2O)

Composition:

Molecular Weight = 3,810.20 gm

Potassium 5.13 % K 6.18 % K₂O

Sodium 3.02 % Na 4.07 % Na₂O

Calcium 2.10 % Ca 2.94 % CaO

Yttrium 23.33 % Y 29.63 % Y₂O₃

Silicon 20.64 % Si 44.15 % SiO₂

Hydrogen 0.42 % H 3.78 % H₂O

Carbon 2.52 % C 9.24 % CO₂

Oxygen 42.83 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

K₅Na₅Y₁₀Ca₂Si₂₈O₇₀(CO₃)₈•8(H₂O)

Environment:

In nepheline syenites.

IMA Status:

Valid Species (Pre-IMA) 1933

Locality:

From Narssarssuk, Greenland. Link to MinDat.org Location Data.

Name Origin:

Named for Frederick Noel Ashcroft (1878-1949), benefactor to the British Museum (Natural History), London, England.

Name Pronunciation:

Ashcroftine-(Y) + Pronunciation

Synonym:

ICSD 202506

PDF 22-508

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Ashcroftine-(Y) Crystallography

Axial Ratios:

a:c = 1:0.72984

Cell Dimensions:

a = 23.994, c = 17.512, Z = 4; V = 10,081.87 Den(Calc)= 2.51

Crystal System:

Tetragonal - Ditetragonal DipyramidalH-M Symbol (4/m 2/m 2/m) Space Group: I 4/mmm

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

By Intensity(I/I_o): 17.1(1), 12.043(0.8), 7.615(0.6),2.687(0.5), 3.114(0.5), 5.379(0.35), 6.014(0.3),

Crystal Structure:

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Moore P B , Sen Gupta P K , Schlemper E O , Merlino S , American Mineralogist , 72 (1987) p.1176-1189, Ashcroftine, ca. K10Na10(Y,Ca)24(OH)4(CO3)16(Si56O140).16H2O, a, structure with enormous polyanions, Sample: investigated by Moore, Sen Gupta, Schlemper

View Additional jPOWD Structure files for Ashcroftine-(Y)
[1]

Physical Properties of Ashcroftine-(Y)

Cleavage:

{100} Perfect, {001} Distinct

Color:

Light violet, Pink, Pinkish brown, Deep violet.

Density:

2.61

Diaphaneity:

Transparent to Translucent

Fracture:

Flexible - Flexible fragments.

Habit:

Fibrous - Crystals made up of fibers.

Habit:

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

Hardness:

5 - Apatite

Luster:

Vitreous - Silky

Streak:

white

Optical Properties of Ashcroftine-(Y)

Gladstone-Dale:

CI meas= -0.035 (Excellent) - where the CI = (1-KPDmeas/KC)
CI calc= -0.076 (Fair) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2158,KPDmeas= 0.2076,KC= 0.2006
Ncalc = 1.5 - 1.52

Optical Data:

Uniaxial (+), w=1.536-1.537, e=1.545-1.549, bire=0.0090-0.0120.

Calculated Properties of Ashcroftine-(Y)

Electron Density:

Bulk Density (Electron Density)=2.54 gm/cc
note: Specific Gravity of Ashcroftine-(Y) =2.61 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_{Ashcroftine-(Y)}= 29.86 barns/electron
U=PE_{Ashcroftine-(Y)} x r_electron= 75.75 barns/cc.

Radioactivity:

GRapi = 71.98 (Gamma Ray American Petroleum Institute Units)
Concentration of Ashcroftine-(Y) per GRapi unit = 1.39 (%)

Estimated Radioactivity from Ashcroftine-(Y) - barely detectable

Ashcroftine-(Y) Classification

Dana Class:

70.03.01.01 (70)Inosilicate Column or Tube Structures

(70.03)with balo-silicates

(70.03.01)Dana Group

70.03.01.01 Ashcroftine-(Y) K5Na5(Y,Ca)12Si28O70(OH)2(CO3)8•8(H2O) I 4/mmm 4/m 2/m 2/m

Strunz Class:

09.DN.15 09 - SILICATES (Germanates)

09.D - Inosilicates* Structural terminology according to Liebau (1985)

09.DN -Inosilicates with 6-periodic double chains

09.DN.15 Ashcroftine-(Ce)* K5Na5(Ce,Ca)12Si28O70(OH)2(CO3)8•8(H2O) I 4/mmm 4/m 2/m 2/m

09.DN.15 Ashcroftine-(Y) K5Na5(Y,Ca)12Si28O70(OH)2(CO3)8•8(H2O) I 4/mmm 4/m 2/m 2/m

Other Ashcroftine-(Y) 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 Ashcroftine-(Y) :
1 - Alkali-Nuts(English)
2 - Alkali-Nuts(Francais)
3 - Am. Min. Crystal Structure Database
4 - Athena
5 - EUROmin Project
6 - GeoScienceWorld
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (UofA)
10 - MinDAT
11 - Mineralienatlas (Deutsch)
12 - Online Mineral Museum
13 - QUT Mineral Atlas
14 - Ruff.Info
15 - WWW-MINCRYST

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Print or Cut-and-Paste your Ashcroftine-(Y) Specimen Label here :

Ashcroftine-(Y)

K5Na5(Y,Ca)12Si28O70(OH)2(CO3)8•8(H2O)
Dana No: 70.03.01.01 Strunz No: 09.DN.15
Locality:

Notes: