Symmetry of Matter

Seven Crystalline Structures	definition
	Triclinic - requires either a center or only translational symmetry. Angles are all different
	Monoclinic - 1 two fold axis of rotation or 1 mirror plane
	Orthorhombic - requires either 3 two fold axis of rotation or 1 two fold axis of rotation and two mirror planes.
	Hexagonal - 6 part symmetry (one 6 fold); all sides are not equal; 60E angles

	Rhombohedral or Trigonal - requires 1 three fold axis of rotation
	Tetragonal - has 2 sides the same and one side different, at 90Eangles requires 1 four fold axis of rotation.
	Cubic or Isometric - 4 three fold axis of rotation. All sides are equal with 90E angles