Round brilliant cut
The standard round diamond cut, with 57 or 58 facets.
How to read it
The FTC’s jewelry guides keep the unqualified words brilliant, brilliant cut and full cut for a round diamond with at least 32 facets plus the table above the girdle and at least 24 below. GIA counts 57 or 58 facets, the 58th being the culet, a tiny facet at the bottom; the table is the large flat facet on top.
Also searched as: brilliant cut, full cut, round brilliant, round diamond.
Grades describe a stone as a grading laboratory saw it. This page explains the grading scales; it doesn’t grade or value any stone.
Where the 58 facets came from
W. R. Cattelle described the same arrangement in 1911: 32 facets and the table above the girdle, 24 and the culet below, fifty-eight in all, which he said nothing had improved on.
Other shapes
GIA calls any shape other than the round brilliant a fancy cut, the best known being the marquise, princess, pear, oval, heart and emerald.
Read next
- Next in Diamond gradingCut grade (Excellent to Poor)The grade for how well a standard round brilliant is cut, from Excellent to Poor.
- The same shape in African flagsFlag of EthiopiaEthiopia’s flag is green, yellow and red in equal horizontal stripes with a blue disc in the centre holding a yellow star of equal lines with yellow rays. Ethiopia’s Flag Proclamation makes the green labour, fertility and development, the yellow hope, justice and equality, and the red sacrifice and heroism for freedom and equality; the blue disc is peace and the star the unity of Ethiopia’s nations, nationalities and peoples.
More diamond grading
The same shape elsewhere
Browse symbols drawn with circles or lines.
Sources
- Guides for the Jewelry, Precious Metals, and Pewter Industries (16 CFR Part 23), 16 CFR Part 23 (1 January 2021 edition), Federal Trade Commission, published by the U.S. Government Publishing Office, § 23.17
- Diamond Cut (GIA 4Cs), Gemological Institute of America
- The Diamond (Cattelle, 1911), W. R. Cattelle, The Diamond, John Lane Company, 1911, Internet Archive (scan), Cutting
Researched, edited and approved by Rory Hansen before publishing. Last reviewed September 27, 2026. How we research
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