Crystal system - Revision history

JohnZ at 00:24, March 14, 2017

2017-03-14T00:24:48Z

DavidB4-bot: /* top */Spelling/Grammar Check, typos fixed: the the → the

2016-07-15T14:46:51Z

top: Spelling/Grammar Check, typos fixed: the the → the

BrianCo: expand and merge from Crystal Systems

2007-07-15T17:25:02Z

expand and merge from Crystal Systems

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'''Crystal systems''' are a way of characterising the the three-dimensional shape shape of mineral crystals by their symmetry and thus aiding in their classification. Mineral crystals come in a seemingly infinite range of shapes. But behind this tremendous diversity of form there is a strict order, because crystals always grow according to simple mathematical laws.<ref>Chesterman, Charles W. ''The Audubon Society Field Guide to North American Rocks and Minerals'', Alfred A. Knopf: New York (1987) ''p. 33''</ref>

There are 6 (or 7)<ref>U.S. classification usually put [[trigonal system|trigonal]] as a sub-set of the [[hexagonal system]], whereas, British practice is to make it a separate class.</ref> crystal systems:

*[[Hexagonal system|Hexagonal]], requires 1 sixfold axis of rotation.
*[[Isometric system|Isometric or cubic]], requires 4 threefold axes of rotation.
*[[Monoclinic system|Monoclinic]], requires either 1 twofold axis of rotation or 1 mirror plane.
*[[Orthorhombic system|Orthorhombic]], requires either 3 twofold axes of rotation or 1 twofold axis of rotation and two mirror planes.
*[[Trigonal system|Trigonal or rhombohedral]], requires 1 threefold axis of rotation.
*[[Tetragonal system|Tetragonal]], requires 1 fourfold axis of rotation.
*[[Triclinic system|Triclinic]], all cases not satisfying the requirements of any other system; thus there is no other symmetry than translational symmetry, or the only extra kind is inversion.

==Notes & References==
<references/>
[[Category:Crystallography]]

← Older revision		Revision as of 14:46, July 15, 2016
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−	'''Crystal systems''' are a way of characterising ~~the~~ the three-dimensional shape shape of mineral crystals by their symmetry and thus aiding in their classification. Mineral crystals come in a seemingly infinite range of shapes. But behind this tremendous diversity of form there is a strict order, because crystals always grow according to simple mathematical laws.<ref>Chesterman, Charles W. ''The Audubon Society Field Guide to North American Rocks and Minerals'', Alfred A. Knopf: New York (1987) ''p. 33''</ref>	+	'''Crystal systems''' are a way of characterising the three-dimensional shape shape of mineral crystals by their symmetry and thus aiding in their classification. Mineral crystals come in a seemingly infinite range of shapes. But behind this tremendous diversity of form there is a strict order, because crystals always grow according to simple mathematical laws.<ref>Chesterman, Charles W. ''The Audubon Society Field Guide to North American Rocks and Minerals'', Alfred A. Knopf: New York (1987) ''p. 33''</ref>

	There are 6 (or 7)<ref>U.S. classification usually put [[trigonal system\|trigonal]] as a sub-set of the [[hexagonal system]], whereas, British practice is to make it a separate class.</ref> crystal systems:		There are 6 (or 7)<ref>U.S. classification usually put [[trigonal system\|trigonal]] as a sub-set of the [[hexagonal system]], whereas, British practice is to make it a separate class.</ref> crystal systems:

@@ Line 1: / Line 1: @@
-'''Crystal systems''' are a way of characterising the three-dimensional shape shape of mineral crystals by their symmetry and thus aiding in their classification. Mineral crystals come in a seemingly infinite range of shapes. But behind this tremendous diversity of form there is a strict order, because crystals always grow according to simple mathematical laws.<ref>Chesterman, Charles W. ''The Audubon Society Field Guide to North American Rocks and Minerals'', Alfred A. Knopf: New York (1987) ''p. 33''</ref>
+'''Crystal systems''' are a way of characterising the three-dimensional shape of mineral crystals by their symmetry, thus aiding their classification. Mineral crystals come in a seemingly infinite range of shapes, but behind this tremendous diversity of form there is a strict order, because crystals always grow according to simple mathematical laws.<ref>Chesterman, Charles W. ''The Audubon Society Field Guide to North American Rocks and Minerals'', Alfred A. Knopf: New York (1987) ''p. 33''</ref>
-There are 6 (or 7)<ref>U.S. classification usually put [[trigonal system|trigonal]] as a sub-set of the [[hexagonal system]], whereas, British practice is to make it a separate class.</ref> crystal systems:
+There are 6 (or 7)<ref>U.S. classification usually put [[trigonal system|trigonal]] as a sub-set of the [[hexagonal system]], whereas British practice is to make it a separate class.</ref> crystal systems:
 *[[Hexagonal system|Hexagonal]], requires 1 sixfold axis of rotation.
@@ Line 11: / Line 11: @@
 *[[Triclinic system|Triclinic]], all cases not satisfying the requirements of any other system; thus there is no other symmetry than translational symmetry, or the only extra kind is inversion.
-==Notes & References==
+==Notes & references==
 <references/>
 [[Category:Crystallography]]