GEOLOGY
CRYSTALLOGRAPHY
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Question
[CLICK ON ANY CHOICE TO KNOW THE RIGHT ANSWER]
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{111}
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{010}
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{100}
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{121}
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Detailed explanation-1: -The symbol (111) represents Miller indices for an infinite set of parallel planes, with intercepts 1, 1 & 1 along the three crystallographic axis (unit lattice parameter along these), which pass through lattice points. It is usually for an infinite set of parallel planes, with a specific ‘d’ spacing.
Detailed explanation-2: -Fluorite can be split along its four cleavage planes into diamond-shaped, eight-sided forms (octahedrons). Fluorite is commonly gray, white, or colorless, but it may also be green, blue, purple, pink, or yellow. The streak is colorless and the luster glassy.
Detailed explanation-3: -Dodecahedral cleavage occurs on the 110 crystal planes forming dodecahedra for a crystal with cubic symmetry. For lower-symmetry crystals, there will be a smaller number of 110 planes.
Detailed explanation-4: -The Miller indices of the planes ABC’, ABC, ABC”, AA"BB” are (112), (111), (221), (110), respectively. These planes have AB, or [11¯0], as common zone axis.