Eucryptite Mineral Data

General Eucryptite Information

Chemical Formula:

LiAlSiO4

Composition:

Molecular Weight = 126.01 gm

Lithium 5.51 % Li 11.86 % Li₂O

Aluminum 21.41 % Al 40.46 % Al₂O₃

Silicon 22.29 % Si 47.68 % SiO₂

Oxygen 50.79 % O

______ ______

100.00 % 100.00 % = TOTAL OXIDE

Empirical Formula:

LiAlSiO₄

Environment:

In lithium-rich pegmatites. Secondary mineral derived from spodumene.

IMA Status:

Valid Species (Pre-IMA) 1880

Locality:

Branchville, Faifield Co., Connecticut, USA. Link to MinDat.org Location Data.

Name Origin:

Named from the Greek for well and concealed, in reference to its occurrence as intimate intergrowths with albite.

Name Pronunciation:

Eucryptite + Pronunciation

Synonym:

ICSD 30982

PDF 14-667

Eucryptite Image

Images:

Eucryptite

Comments: Gray massive eucryptite.
Location: Parker Mountain, Center Strafford, Strafford County, New Hampshire, USA. Scale: See Photo.
© Jeff Weissman / Photographic Guide to Mineral Species

Images:

Eucryptite

Comments: Fine grained, massive eucryptite. Fluorescent Red under SW.
Location: Midnight Owl mine, Yavapai Co., Arizona, USA. Scale: 6x4x4cm.
© Tom Loomis / Dakota Matrix

Eucryptite Crystallography

Axial Ratios:

a:c = 1:0.66773

Cell Dimensions:

a = 13.48, c = 9.001, Z = 18; V = 1,416.45 Den(Calc)= 2.66

Crystal System:

Trigonal - Rhombohedral H-M Symbol ( 3) Space Group: R 3

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

By Intensity(I/I_o): 3.362(1), 3.965(0.9), 2.733(0.7),

Physical Properties of Eucryptite

Cleavage:

{1011} Indistinct

Color:

Brown, Colorless, White.

Density:

2.67

Diaphaneity:

Transparent to translucent

Fracture:

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

Hardness:

6.5 - Pyrite

Luminescence:

Fluorescent, Short UV=pink, Long UV=pink.

Luster:

Vitreous (Glassy)

Magnetism:

Nonmagnetic

Streak:

white

Optical Properties of Eucryptite

Gladstone-Dale:

CI meas= 0.05 (Good) - where the CI = (1-KPDmeas/KC)
CI calc= 0.046 (Good) - where the CI = (1-KPDcalc/KC)
KPDcalc= 0.2092,KPDmeas= 0.2084,KC= 0.2193
Ncalc = 1.58 - 1.59

Optical Data:

Uniaxial (+), w=1.527, e=1.586, bire=0.0590.

Calculated Properties of Eucryptite

Electron Density:

Bulk Density (Electron Density)=2.62 gm/cc
note: Specific Gravity of Eucryptite =2.66 gm/cc.

Fermion Index:

Fermion Index = 0.01
Boson Index = 0.99

Photoelectric:

PE_Eucryptite= 1.52 barns/electron
U=PE_Eucryptite x rElectron Density= 3.98 barns/cc.

Radioactivity:

GRapi = 0 (Gamma Ray American Petroleum Institute Units)
Eucryptite is Not Radioactive

Eucryptite Classification

Dana Class:

51.01.01.03 (51)Nesosilicate Insular SiO4 Groups Only

(51.01)with cations in [4] coordination

(51.01.01)Phenakite group

51.01.01.01 Phenakite Be2SiO4 R 3 3

51.01.01.02 Willemite Zn2SiO4 R 3 3

51.01.01.03 Eucryptite LiAlSiO4 R 3 3

Strunz Class:

09.AA.05 09 - SILICATES (Germanates)

09.A - Nesosilicates

09.AA -Nesosilicates without additional anions;

09.AA.05 Eucryptite LiAlSiO4 R 3 3

09.AA.05 Phenakite Be2SiO4 R 3 3

09.AA.05 Willemite Zn2SiO4 R 3 3

Other Eucryptite Information

References:

NAME( Ford32) PHYS. PROP.(Enc. of Minerals,2nd ed.,1990) OPTIC PROP.(Enc. of Minerals,2nd ed.,1990)

See Also:

Links to other databases for Eucryptite :
1 - Am. Min. Crystal Structure Database
2 - Amethyst Galleries' Mineral Gallery
3 - Athena
4 - EUROmin Project
5 - GeoScienceWorld
6 - Glendale Community College
7 - Google Images
8 - Google Scholar
9 - Handbook of Mineralogy (MinSocAm)
10 - Handbook of Mineralogy (UofA)
11 - MinDAT
12 - Mineralienatlas (Deutsch)
13 - Online Mineral Museum
14 - QUT Mineral Atlas
15 - Ruff.Info
16 - WWW-MINCRYST

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

Eucryptite

LiAlSiO4
Dana No: 51.01.01.03 Strunz No: 09.AA.05
Locality:

Notes:

Dakota Matrix
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