Laws of crystallography

2. Law of constancy of interfacial angle:
This law states that angle between adjacent corresponding faces is inter facial
angles of the crystal of a particular substance is always constant inspite of
different shapes and sizes and mode of growth of crystal.

3. Law of rational indices:
It states that the intercept made by any crystallographic axis to crystal face will
always be represented in whole number.

4. Law of constancy of symmetry:
This law states that all crystals of a substance have the same elements of
symmetry is plane of symmetry, axis of symmetry and centre of symmetry.
Cube
1. Axis of symmetry – 13
2. Plane of symmetry – 9
3. Centre of symmetry – 1
Total - 23

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