That is the valley between her breasts.
The area between a woman's breasts is commonly referred to as the cleavage.
This phrase means to "take a look" at something, and I believe the deco part comes from the word decolletage which means the low cut neckline on a womans dress. So to have a deco, is to look at a womans cleavage and the use of the term has been extended over the years to mean have a look at anything. Steve Hennessy-Liverpool
Sulfur's cleavage is imperfect.
Cleavage is a mineral's tendency to break along flat, parallel surfaces (cleavage planes). Excellent cleavage direction reflects light in one direction, it is considered basal, or book cleavage. Biotite and muscovite have excellent cleavage. Good cleavage reflects light in one direction from a set of many small flat surfaces, augite and gypsum are examples. Poor cleavage directions reflect light form surfaces that are hard to detect, and this is true for sulfur.
A cleavage is a natural division or indentation in rocks, minerals, or crystals that forms due to geological processes. It represents a tendency of certain materials to break along parallel planes, often resulting in smooth surfaces. Cleavage is related to the internal structure of the material and how its atoms are arranged.
cleavage....
it has no cleavage
imperfect cleavage
it has no cleavage
What cleavage does pyrite have
cleavage
No it has cleavage and it's cleavage is "absent".