If these minerals are dropped, the breaks that occur are along the weakest areas. This is cleavage. Fractures are breaks that occur when there is no weakness in a particular mineral at all, meaning that an outside source has caused the break.
When a fracture occurs, there are no two pieces that are similar. All are going to be different angles and sizes. There are five basic forms of cleavage that include: one directional, two directional, three directional, cubic, and octahedral. If a mineral has one directional cleavage, it peels as in layers. Three dimensional breaks are breaks in three directions with right angles at each.
Cubic cleavage is done when a mineral breaks into the shape of a perfect cube with four right angles. Octahedral cleavage is done when a mineral breaks into many pyramids and is the hardest to detect.
Like cleavage there are two types of fractures; conchoidal and non-conchoidal. Conchoidal fractures take a round shape to the break, like if a bottle is broken on the ground.
Key Difference: In mineralogy, cleavage and fracture both describe a tendency of a mineral to break. On the other hand, fracture breaks a mineral along the curved surface with irregular shapes. Cleavage is often measured by three factors: Quality of cleavage Number of sides exhibiting cleavage Cleavage habit It is also important to describe the angle between the cleavage planes. Comparison between Cleavage and Fracture: Cleavage Fracture Definition In cleavage, a mineral may split apart along various smooth planes.
Types There are five types of cleavage: Basal or pinacoidal — It occurs parallel to the base of a crystal Cubic Cleavage — It occurs parallel to the faces of a cube for a crystal with cubic symmetry. Octahedral Cleavage — It occurs on the crystal planes and octahedral shapes are formed.
Dodecahedral Cleavage - It occurs on the crystal pleanes and dodecahedra shapes are formed. Rhombohedral cleavage — It occurs parallel to the faces of a rhombohedron. Prismatic cleavage - It is a cleavage that is parallel to a vertical prism There are five types of fracture: Conchoidal - A fracture resembling a semicircular shell, with a smooth, curved surface.
Uneven - A fracture that leaves a rough or irregular surface. A mineral can also have different types of a fracture. Home Education Difference between Cleavage and Fracture. By: Editorial Staff Updated: May, Cleavage Fracture Breaking or splitting of minerals in crystallized shape Breaking of a mineral in an irregular way, or chipping Mostly full, smooth edges Mostly jagged edges Has almost none to very few rough surfaces Has a lot of rough surfaces.
Did this article help you? Yes No. Current rating: 6. Thank you! What was wrong? Cleavage and fracture are important tools you can use to identify minerals, but you don't need to break your specimens to see this.
Take a closer look, you should be able to see cleavage or fracture on any broken surface. To find out about minerals you should Take a closer look , and then find out about some of their properties Cleavage and fracture When crystals break, they can either split leaving a clean, flat face called a cleavage plane, or fracture leaving a more rough, uneven surface.
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