Lithium Aluminium Silicate
LiAl(SiO3)2
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Chemical name
Lithium Aluminium Silicate |
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Mineral name
Spodumene |
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Chemical formula
LiAl(SiO3)2 |
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Crystal system
monoclinic |
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Crystal Class
monoclinic-prismatic (2/m) |
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Space Group
C2/c |
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Unit cell
a [Å]:9.52 b [Å]:8.32 c [Å]:5.25 |
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Molecular weight [g/mol]
186.1 |
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Formula units
Z=4 |
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Frequent crystal surfaces
{100}, {010}, {110} |
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Twinning
common on {100} |
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Mohs hardness
6.5 - 7 |
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Density [g/cm3]
3.1 - 3.2 |
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Cleavage
perfect on {110} |
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Fracture / Tenacity
uneven to conchoidal |
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Color
colorless to grayish-white, rose to violett, green |
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Streak
white |
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Transparency
transparent to translucent |
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Luster
vitreous, pearly on cleavage surfaces |
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Optical character
biaxial (+) |
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Refractive Index
nα=1.648-1.661; nβ=1.655-1.670; nΥ=1.662-1.670 |
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Birefringence δ
0.014 - 0.018 |
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Pleochroism δ
strong |
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Other
often fluorescent (kunzite) |
