Lepidocrocite - Gamma iron oxy Hydroxide
γ-FeO(OH)
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Crystal symmetry
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Orthorhombic (2/m 2/m 2/m) - dipyramidal
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Unit cell
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a = 3.88 Å b = 12,54 Å c = 3.07 Å Z = 4
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Identifikation
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Color
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Ruby-red
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Crystal habit
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Flattened scales aggregated
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Crystal sytem
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orthorhombic
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Cleavage
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{010} Perfect
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Mohs scale hardness
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5
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Diaphaneity
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Transparent
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Specific gravity
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4
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Optical properties
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Biaxial (-)
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Refractive index
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nα =1.940 nβ = 2.200 nγ = 2.510
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Birefrigence
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δ = 0,570
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Pleochroism
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Strong; X = colorless to yellow Y= orange, yellow, dark red-orange Z = orange, yellow, darker red-orange
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2V angle
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Measured: 83°
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