Bruting is shaping the outline of a diamond, usually round, by grinding it against another diamond.
In more detail
By hand, nobody could make a true circle, so early brilliants were cushion-shaped. Mechanical bruting in the 1870s made diamonds truly round. In Boston, Charles Field, foreman for Henry Morse, built one such machine. A bruted girdle keeps the surface from this process.
On a grading report
The proportion diagram can describe a girdle as bruted.
Related terms
- Girdle: The girdle is the narrow band at the widest part of a cut stone, between the crown and the pavilion. It is the edge that a setting grips.
- Old European cut: An old European cut is an antique round diamond with 58 facets, from the 1870s to about 1930. The bruting machine made its round outline possible.
- Old mine cut: An old mine cut is an antique cushion-shaped diamond of the 1700s and 1800s. It has the Peruzzi's 58 facets, cut more evenly by hand.
- Round brilliant: A round brilliant is a round diamond with the brilliant facet plan. It has 33 crown and 24 pavilion facets: 57 in all, or 58 with a culet.