Mineralogists, however, have devised a method to help them identify minerals in the field which uses a few basic techniques geared to the physical properties of minerals. These properties include, but are not restricted to, the habit, form, cleavage, parting, fracture, hardness, specific gravity, color, luster and streak of the minerals. All of these properties are in reference to an individual mineral. This property applies to the external shape of the mineral's growth, and it is determined by visual observation. This refers to the geometric shapes that make up a mineral crystal.
Form is also visually determined.
This property refers to the mineral's disposition to break along planes of weakness at the atomic scale. This weakness may be caused by an imperfect atomic bonding of some of its planes, thereby disposing the mineral to break at these weaker spots. All specimens of a specific mineral have this property. This also refers to the mineral's disposition to break along specific planes of structural weakness. This particular weakness, however, is due to the growth history of a particular specimen and does not necessarily apply to every specimen of this mineral.