Point Group For The students

Symmetry Elements
We may have the following combinations:
X rotation axis alone
X inversion axis alone
X/m rotation axis normal to a plane of symmetry
Xm rotation axis with a vertical plane of symmetry
Xm inversion axis with a vertical plane of symmetry
X2 rotation axis with a diad axis normal to it
X/mm rotation axis with both kinds of plane symmetry

Space Group

SCREW AXIS

Glide Plane

The point and monoclinic space group

Class m; the crystallographic axes, showing their relationship to the plane of symmetry, and a stereogram of the general form

Orthorhombic Class mm

A crystal of
potassium tetrathionate
A crystal of
Na2SiO2.5H2O
A crystal of
hilgardite

Pritsm

Different combination of The Cubic Point group

Class 432 the elements of symmetry, crystallographic axes and a stereogram of the general form

Class m3m; the elements of symmetry, crystallographic axes and a stereogram of the general form