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 % K2 O
Sodium 3.02 % Na 4.07 % Na2 O
Calcium 2.10 % Ca 2.94 % CaO
Yttrium 23.33 % Y 29.63 % Y2 O3
Silicon 20.64 % Si 44.15 % SiO2
Hydrogen 0.42 % H 3.78 % H2 O
Carbon 2.52 % C 9.24 % CO2
Oxygen 42.83 % O
______ ______
100.00 % 100.00 % = TOTAL OXIDE
Empirical Formula:
K5 Na5 Y10 Ca2 Si28 O70 (CO3 )8 •8(H2 O)
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
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 Dipyramidal H-M Symbol (4/m 2/m 2/m) Space Group: I 4/mmm
X Ray Diffraction:
By Intensity(I/Io ): 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),
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:
PEAshcroftine-(Y) = 29.86 barns/electronU=PEAshcroftine-(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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Ashcroftine-(Y)
K5Na5(Y,Ca)12Si28O70(OH)2(CO3)8•8(H2O)
Dana No: 70.03.01.01 Strunz No: 09.DN.15
Locality:
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