mineralogy Mineralogy is a subject of geology specializing in the scientific study of the chemistry, crystal structure, and physical (including optical mineralogy, optical) properties of minerals and mineralized artifact (archaeology), artifacts. Specific s ...

, tenacity is a

mineral In geology and mineralogy, a mineral or mineral species is, broadly speaking, a solid substance with a fairly well-defined chemical composition and a specific crystal structure that occurs naturally in pure form.John P. Rafferty, ed. (2011): Mi ...

's behavior when deformed or broken.

Common terms

Brittleness

The mineral breaks or powders easily. Most ionic-bonded minerals are brittle.

Malleability

The mineral may be pounded out into thin sheets. Metallic-bonded minerals are usually malleable.

Ductility

The mineral may be drawn into a wire. Ductile materials have to be malleable as well as tough.

Sectility

May be cut smoothly with a knife. Relatively few minerals are sectile. Sectility is a form of tenacity and can be used to distinguish minerals of similar appearance.

Gold Gold is a chemical element; it has chemical symbol Au (from Latin ) and atomic number 79. In its pure form, it is a brightness, bright, slightly orange-yellow, dense, soft, malleable, and ductile metal. Chemically, gold is a transition metal ...

, for example, is sectile but pyrite ("fool's gold") is not.

Elasticity

If bent by an external force, an elastic mineral will spring back to its original shape and size when the stress, that is, the external force, is released.

Plasticity

If bent by an external force, a plastic mineral will not spring back to its original shape and size when the stress, that is, the external force, is released. It stays bent.

References

Mineralogy Deformation (mechanics) Materials science {{mineralogy-stub