Cleavage (breasts)

Cleavage is the area between a woman's breasts lying over the sternum, and normally refers to what is visible with clothing that includes a low-cut neckline. In some cultures, display of cleavage is considered aesthetic or erotic, and may be associated with garments with low necklines that expose or highlight cleavage, such as ball gowns, evening gowns, lingerie, and swimwear. In these cultures, women have throughout history sought to enhance their physical attractiveness and femininity, within the context of changing fashions and cultural-specific norms of modesty of the time and place. The methods practised in appropriate contexts have included the accentuation and partial display of breasts, including cleavage. In some cultures any display of cleavage may be culturally taboo, illegal or otherwise socially disapproved.

Terminology

The anatomical term for the area that constitutes a cleavage is intermammary cleft, intermammary sulcus or sulcus intermammarius.

Décolletage is the upper part of a woman's torso, between her waist and neck, comprising her neck, shoulders, back and chest, that is exposed by the neckline of her clothing. However, the term is most commonly applied to a neckline that reveals or emphasizes cleavage.

Cleavage

Cleavage may refer to:

Cleavage (crystal)

Cleavage, in mineralogy, is the tendency of crystalline materials to split along definite crystallographic structural planes. These planes of relative weakness are a result of the regular locations of atoms and ions in the crystal, which create smooth repeating surfaces that are visible both in the microscope and to the naked eye.

Types of cleavage

Cleavage forms parallel to crystallographic planes:

Cleavage (geology)

Cleavage, in structural geology and petrology, describes a type of planar rock feature that develops as a result of deformation and metamorphism. The degree of deformation and metamorphism along with rock type determines the kind of cleavage feature that develops. Generally these structures are formed in fine grained rocks composed of minerals affected by pressure solution.

Cleavage is a type of rock foliation, a fabric element that describes the way planar features develop in a rock. Foliation is separated into two groups: primary and secondary. Primary deals with igneous and sedimentary rocks while secondary deals with rocks that undergo metamorphism as a result of deformation. Cleavage is a type of secondary foliation associated with fine grained rocks. For coarser grained rocks, schistosity is used to describe secondary foliation.

There is a variety of definitions for cleavage which may cause confusion and debate. The terminology used in this article is based largely on Passchier and Trouw (2005). They state that cleavage is a type of secondary foliation in fine grained rocks characterized by planar fabric elements that form in a preferred orientation. Some authors chose to use cleavage when describing any form of secondary foliation.