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gptkbp:instanceOf
|
phyllosilicate mineral
mica group mineral
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gptkbp:alteration
|
can alter to chlorite
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gptkbp:associatedMinerals
|
gptkb:muscovite
feldspar
quartz
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gptkbp:birefringence
|
δ = 0.03–0.07
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gptkbp:category
|
silicate mineral
|
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gptkbp:chemicalFormula
|
K(Mg,Fe)3AlSi3O10(F,OH)2
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gptkbp:cleavage
|
perfect basal
|
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gptkbp:color
|
black
dark brown
|
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gptkbp:crystalSystem
|
monoclinic
|
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gptkbp:diaphaneity
|
transparent to opaque
|
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gptkbp:event
|
metamorphic rocks
igneous rocks
|
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gptkbp:fracture
|
uneven
|
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gptkbp:hardnessMohs
|
2.5–3
|
|
https://www.w3.org/2000/01/rdf-schema#label
|
Biotite
|
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gptkbp:IMA_symbol
|
Bt
|
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gptkbp:luster
|
vitreous
pearly
|
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gptkbp:magnetType
|
weakly magnetic
|
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gptkbp:namedAfter
|
gptkb:Jean-Baptiste_Biot
|
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gptkbp:opticalProperties
|
biaxial (-)
|
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gptkbp:pleochroism
|
strong
|
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gptkbp:radioactive
|
may contain trace amounts of radioactive elements
|
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gptkbp:refractiveIndex
|
nα = 1.56–1.62
nβ = 1.59–1.66
nγ = 1.60–1.69
|
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gptkbp:relatedGroup
|
mica group
|
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gptkbp:solubility
|
insoluble in water
|
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gptkbp:specificGravity
|
2.7–3.1
|
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gptkbp:streak
|
white
|
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gptkbp:tenacity
|
elastic
|
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gptkbp:transparency
|
transparent to opaque
|
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gptkbp:uses
|
insulator
geological indicator
|
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gptkbp:bfsParent
|
gptkb:Jean-Baptiste_Biot
gptkb:Muscovite
|
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gptkbp:bfsLayer
|
5
|