Crystal System and Crystal Form

Appearance of the faces on a crystal is described in terms of forms and habit.  Understanding of these terms are important when observing rough gem material.

Crystal Form is the outer or surface layer of a crystal.

Crystal Habit of a crystal or set of crystals is the overall shape.  This shape is made of the crystal form or forms with which it has grown.


Crystal system - seven classification of crystal system
Cubic
Trigonal
Hexagonal
Orthorhombic
Monoclinic
Triclinic

Crystal Form - It is the outer surface of the crystal structure and is a set of crystal faces related by symmetry.
Cube
Octahedral
Dodecahedron
Tetra hexahedron
Icositetrahedron