Bruting
 
Bruting involves the shaping of the base of a diamond, by which it more or less receives its form as a polished diamond. The circumference of the cut stone forms the shape of the girdle, which is the narrow band that encompasses the edge of the plane separating the crown and the pavilion of a polished gemstone.

The manual method of bruting involves placing a diamond with the aid of a cap into the cup of a lathe. Another diamond is affixed to a long wooden rod and brought into contact with the turning stone in the lathe.

Most bruting today is done mechanically. This typically is a performed by bringing two diamonds, each attached to a lathe and turning in opposite directions, in contact with one another. The contact between the two stones is carefully monitored. As one of the stones reaches is required diameter, the process is stopped and the stone is replaced.

More modern cutting methods involve laser beams. In this case, the diamond is moved along a predetermined line within the path of the laser beam. Laser cutting enables the creation of non-elliptical shaped polished diamonds, like stars.
 
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