---
title: "Bruting: meaning in gemology"
description: "Bruting is shaping the outline of a diamond, usually round, by grinding it against another diamond."
url: https://digitalgemology.com/learn/glossary/bruting
image: https://digitalgemology.com/img/og-digital-gemology.png?v=d224fb01
---

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[Glossary](https://digitalgemology.com/learn/glossary) · Cuts and shapes

# Bruting

Also called girdling, bruting machine

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](https://digitalgemology.com/learn/glossary/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](https://digitalgemology.com/learn/glossary/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](https://digitalgemology.com/learn/glossary/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](https://digitalgemology.com/learn/glossary/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.

## Learn more

- [Old European cut diamonds: when the outline went round](https://digitalgemology.com/learn/historic-cuts/old-european-cut-diamond)
- [The Mazarin cut: the first brilliant](https://digitalgemology.com/learn/historic-cuts/mazarin-cut-diamond)
- [Diamond girdle thickness: thin, medium, thick and what it costs you](https://digitalgemology.com/learn/diamond-anatomy/diamond-girdle-thickness)

[All 328 terms](https://digitalgemology.com/learn/glossary)