Form - Revision history

BrianMcMahon: Tidied translations.

2017-11-13T13:38:18Z

Tidied translations.

← Older revision		Revision as of 13:38, 13 November 2017
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	<font color="blue">Forme</font> (''Fr''); <font color="red">Kristallform </font> (''Ge''); <font color="black">Forma</font> (''It''); <font color="purple">結晶形</font> (''Ja'').		<font color="blue">Forme</font> (''Fr''). <font color="red">Kristallform </font> (''Ge''). <font color="black">Forma</font> (''It''). <font color="purple">結晶形</font> (''Ja'').

	==Definition==		==Definition==

MassimoNespolo: bipyramid -> dipyramid (to follow more closely ITA)

2017-11-05T09:25:29Z

bipyramid -> dipyramid (to follow more closely ITA)

← Older revision		Revision as of 09:25, 5 November 2017
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	\|Rhombic disphenoid \|\|Rhombic disphenoid\|\|222		\|Rhombic disphenoid \|\|Rhombic disphenoid\|\|222
	\|-		\|-
	\|Rhombic ~~bipyramid~~ \|\|Rectangular prism\|\|''mmm''		\|Rhombic dipyramid \|\|Rectangular prism\|\|''mmm''
	\|-		\|-
	\|Trigonal ~~bipyramid~~ \|\|Trigonal prism\|\|<math>\bar62m</math>		\|Trigonal dipyramid \|\|Trigonal prism\|\|<math>\bar62m</math>
	\|-		\|-
	\|Tetragonal ~~bipyramid~~ \|\|Tetragonal prism\|\|4/''mmm''		\|Tetragonal dipyramid \|\|Tetragonal prism\|\|4/''mmm''
	\|-		\|-
	\|Hexagonal ~~bipyramid~~ \|\|Hexagonal prism\|\|6/''mmm''		\|Hexagonal dipyramid \|\|Hexagonal prism\|\|6/''mmm''
	\|-		\|-
	\|Ditrigonal ~~bipyramid~~ \|\|Edge-truncated trigonal prism\|\|<math>\bar62m</math>		\|Ditrigonal dipyramid \|\|Edge-truncated trigonal prism\|\|<math>\bar62m</math>
	\|-		\|-
	\|Ditetragonal ~~bipyramid~~ \|\|Edge-truncated tetragonal prism\|\|4/''mmm''		\|Ditetragonal dipyramid \|\|Edge-truncated tetragonal prism\|\|4/''mmm''
	\|-		\|-
	\|Dihexagonal ~~bipyramid~~ \|\|Edge-truncated hexagonal prism\|\|6/''mmm''		\|Dihexagonal dipyramid \|\|Edge-truncated hexagonal prism\|\|6/''mmm''
	\|-		\|-
	\|Tetragonal disphenoid \|\|Tetragonal disphenoid \|\|<math>\bar42m</math>		\|Tetragonal disphenoid \|\|Tetragonal disphenoid \|\|<math>\bar42m</math>

MassimoNespolo: lang

2017-10-12T10:01:16Z

lang

← Older revision		Revision as of 10:01, 12 October 2017
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	<font color="blue">Forme</font> (''Fr''). <font color="black">Forma</font> (''It''). <font color="purple">結晶形</font> (''Ja'').		<font color="blue">Forme</font> (''Fr''); <font color="red">Kristallform </font> (''Ge''); <font color="black">Forma</font> (''It''); <font color="purple">結晶形</font> (''Ja'').

	==Definition==		==Definition==

BrianMcMahon at 08:37, 21 May 2017

2017-05-21T08:37:13Z

← Older revision		Revision as of 08:37, 21 May 2017
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	*Boldyrev, A. K. (1936). ''Am. Mineral.'' '''21''', 731-734 (rejection of the dihedron splitting)		*Boldyrev, A. K. (1936). ''Am. Mineral.'' '''21''', 731-734 (rejection of the dihedron splitting)
	*Donnay, J. D. H. and Takeda, H. (1965). ''Mineral. J.'' '''4''', 291-298 (rejection of the dihedron splitting)		*Donnay, J. D. H. and Takeda, H. (1965). ''Mineral. J.'' '''4''', 291-298 (rejection of the dihedron splitting)
	*Nespolo, M. (2015). ''J. Appl. Crystallogr.'' '''48''', 1290-1298 (47 geometric ''vs'' 130 affine forms).		*Nespolo, M. (2015). ''J. Appl. Crystallogr.'' '''48''', 1290-1298 (47 geometric ''vs'' 130 affine forms)

	[[Category:Fundamental crystallography]]		[[Category:Fundamental crystallography]]
	[[Category:Morphological crystallography]]		[[Category:Morphological crystallography]]

BrianMcMahon: Style edits to align with printed edition

2017-05-15T11:21:18Z

Style edits to align with printed edition

Show changes

MassimoNespolo: /* See also */ 6th edition of ITA

2017-04-10T15:40:39Z

MassimoNespolo: discussion about the 47 vs. 48 face forms.

2016-08-25T14:48:04Z

discussion about the 47 vs. 48 face forms.

← Older revision		Revision as of 14:48, 25 August 2016
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	==List of crystal (face) and point forms==		==List of crystal (face) and point forms==
	The list of face forms includes 47 ~~or 48~~ forms~~, depending on whether the dihedron is separated into sphenoid and dome or not~~.		The list of face forms includes 47 forms.

	===Open face forms and their dual point forms===		===Open face forms and their dual point forms===
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	<small>'''Note''': the disphenoids are sometimes improperly called "tetrahedra"</small>		<small>'''Note''': the disphenoids are sometimes improperly called "tetrahedra"</small>

			== Discussion ==
			Some texts show 48 forms instead of 47 because the dihedron is separated into sphenoid and dome depending on the handedness of the faces. This is however inconsistent and has been repeatedly criticized, because such a splitting has to be applied to all the forms (leading to 130 affine forms), or to none (47 geometric forms).

	== See also ==		== See also ==
	*Chapter 10 in the ''International Tables for Crystallography'', Volume A		*Chapter 10 in the ''International Tables for Crystallography'', Volume A
			*A.K. Boldyrev, Am. Mineral. 21 (1936) 731-734 (rejection of the dihedron splitting)
			*J.D.H. Donnay and H. Takeda, Mineral. J. 4 (1965) 291-298 (rejection of the dihedron splitting)
			*M. Nespolo, J. Appl. Crystallogr. 48 (2015) 1290-1298 (47 geometric vs. 130 affine forms).

	[[Category:Fundamental crystallography]]		[[Category:Fundamental crystallography]]
	[[Category:Morphological crystallography]]		[[Category:Morphological crystallography]]

MassimoNespolo: /* Closed face forms and their dual point forms */ name update as in ITA6

2016-06-24T10:08:01Z

Closed face forms and their dual point forms: name update as in ITA6

← Older revision		Revision as of 10:08, 24 June 2016
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	\|Rhombic disphenoid \|\|Rhombic disphenoid\|\|222		\|Rhombic disphenoid \|\|Rhombic disphenoid\|\|222
	\|-		\|-
	\|Rhombic bipyramid \|\|~~Quad~~\|\|''mmm''		\|Rhombic bipyramid \|\|Rectangular prism\|\|''mmm''
	\|-		\|-
	\|Trigonal bipyramid \|\|Trigonal prism\|\|<math>\bar62m</math>		\|Trigonal bipyramid \|\|Trigonal prism\|\|<math>\bar62m</math>

MassimoNespolo: /* Classification of forms */ another typo

2015-02-07T09:50:01Z

Classification of forms: another typo

← Older revision		Revision as of 09:50, 7 February 2015
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	===General vs. special forms===		===General vs. special forms===
	A '''face''' is called '''general''' if only the identity operation transform the face onto itself. Each complete set of symmetrically equivalent general faces is a '''general crystal form'''. The ~~mulplicity~~ (number of faces of the form) of a general form is the order of the point group P. In the [[stereographic projection]], the poles of general faces do not lie on any symmetry element of P.		A '''face''' is called '''general''' if only the identity operation transform the face onto itself. Each complete set of symmetrically equivalent general faces is a '''general crystal form'''. The multiplicity (number of faces of the form) of a general form is the order of the point group P. In the [[stereographic projection]], the poles of general faces do not lie on any symmetry element of P.

	A '''point''' is called '''general''' if its [[site symmetry]] is 1. A '''general point form''' is a complete set of symmetrically equivalent general points.		A '''point''' is called '''general''' if its [[site symmetry]] is 1. A '''general point form''' is a complete set of symmetrically equivalent general points.

MassimoNespolo: /* Classification of forms */ typo

2015-02-07T09:49:00Z

Classification of forms: typo

← Older revision		Revision as of 09:49, 7 February 2015
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	===General vs. special forms===		===General vs. special forms===
	A '''face''' is called '''general''' if only the identity operation transform the face onto itself. Each complete set of ~~symmetrycally~~ equivalent general faces is a '''general crystal form'''. The mulplicity (number of faces of the form) of a general form is the order of the point group P. In the [[stereographic projection]], the poles of general faces do not lie on any symmetry element of P.		A '''face''' is called '''general''' if only the identity operation transform the face onto itself. Each complete set of symmetrically equivalent general faces is a '''general crystal form'''. The mulplicity (number of faces of the form) of a general form is the order of the point group P. In the [[stereographic projection]], the poles of general faces do not lie on any symmetry element of P.

	A '''point''' is called '''general''' if its [[site symmetry]] is 1. A '''general point form''' is a complete set of symmetrically equivalent general points.		A '''point''' is called '''general''' if its [[site symmetry]] is 1. A '''general point form''' is a complete set of symmetrically equivalent general points.

← Older revision		Revision as of 15:40, 10 April 2017
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	== See also ==		== See also ==
	*Chapter 10 in the ''International Tables for Crystallography'', Volume A		*Chapter 3.2 in the ''International Tables for Crystallography'', Volume A, 6<sup>th</sup> edition
	*A.K. Boldyrev, Am. Mineral. 21 (1936) 731-734 (rejection of the dihedron splitting)		*A.K. Boldyrev, Am. Mineral. 21 (1936) 731-734 (rejection of the dihedron splitting)
	*J.D.H. Donnay and H. Takeda, Mineral. J. 4 (1965) 291-298 (rejection of the dihedron splitting)		*J.D.H. Donnay and H. Takeda, Mineral. J. 4 (1965) 291-298 (rejection of the dihedron splitting)