Various types of mineral fractures include:

Conchoidal:

Fracture resembling a semicircular shell, with a smooth, curved surface. An good illustration of a conchoidal fracture is a large chip in a piece of glass. This fracture is also known as "shelly" in some references.

Uneven:

Fracture that leaves a rough or irregular surface.

Hackly:

Fracture that resembles broken metal, with rough, jagged, points. True metals exhibit this fracture. This fracture is also known as "jagged".

Splintery:

Fracture that forms elongated splinters. All fibrous minerals fall into this category.

Crumbly:

Fracture of minerals that crumble when broken.

Even:

Fracture that forms a smooth surface.

Sub-Conchoidal:

Fracture that falls somewhere between conchoidal and even; smooth with irregular rounded corners.

Some references may describe additional fractures not mentioned above, but those terms are either synonymous or simply used as a verbal depiction of the authors inference.

Almost all minerals have a characteristic fracture. Some minerals of the same species may exhibit a different fracture, but this is rare.