Shape · Chapter 10

Old mine cushions, Old European cuts, and the culet

Two antique cuts, the proportions that define them, and the small facet at the base of every diamond that sets them apart from the modern round.

Before the modern round, diamonds were cut by eye and by hand. The result was a different kind of beauty: a higher crown, broader flashes of light, and a small circle at the center of the stone.

What the culet is

The culet is the base of the pavilion, where its facets meet. In a modern round they meet at a point, and the report records the culet as none or pointed. Earlier cutters often polished a small flat facet there instead, which also spared the point from chipping. Laboratories describe its size against the girdle diameter, from none and very small through medium and slightly large to large, very large, and extremely large. Face-up, a culet of any real size shows as a small circle at the center, seen through the table.

Worth remembering: In a modern round, a visible culet is a departure. In an antique cut, it is part of the design.

The old mine cushion

From the early eighteenth century to the late nineteenth, the old mine cut was among the most common ways to fashion a diamond, and it is the stone most often found in Georgian and Victorian jewelry. Its outline is a softened square; its table is small, its crown high, and its culet large and open. Like the modern round it carries fifty-eight facets, but its lower halves are short, so it returns broad, distinct flashes rather than fine sparkle. Its girdle can be very thin in places, which deserves care in the setting.

The Old European cut

The Old European cut arrived in the late nineteenth century, when new cutting methods made a truly round girdle possible. It is round like the modern brilliant, but its table is smaller, its crown higher, and its total depth greater, and its culet is usually open, if smaller than an old mine’s. Face-up it shows a bold, petal-like pattern of light and dark around the center. In the decades that followed, tables grew, culets shrank, and the lower facets lengthened, until the modern round emerged in the middle of the twentieth century.

How a laboratory names them

A laboratory may name an Old European outright. An old mine cut is more often graded simply as a cushion, and the report’s figures tell the rest: a small table, a high crown, and a large or long culet. The Carat Standard reads each report as the laboratory issued it, against the proportions that suit an antique cut, never against the modern round. In the Collection, cushions with that signature are gathered under Old Mine Cushion, so they can be found together.

Period stones and new antique cuts

An antique cut may be a stone of real age, or a new diamond cut today to the old proportions; a laboratory-grown antique cut is, by its nature, new. New antique cuts are often more symmetrical than their predecessors, and many are cut only once ordered. The report describes the diamond, but rarely when it was cut. If age matters to you, ask for its history, and expect a true period stone to show the small irregularities of cutting by hand.

Seeing one well

Antique cuts were made in an age of candle and gaslight, and they reward patience. In a face-up video taken in even light, look for the broad, chunky flashes these cuts are known for, and for how the culet reads at the center: as a small, neat circle, or as a dark spot that draws the eye. A very large culet can begin to look like an opening in the stone. Tilt it slowly; the pattern should move in bold steps rather than shimmer.

Worth remembering: Judge an antique cut on its own terms: bold flashes and a neat culet, not the crisp sparkle of a modern round.

Essential language

Culet: The base of the pavilion: a point, or a small flat facet polished there.
Open culet: A culet facet large enough to be seen face-up as a small circle at the center.
Old mine cut: An antique cut with a softened square outline, small table, high crown, and large culet; often graded as a cushion.
Old European cut: An antique round with a small table, high crown, greater depth, and an open culet.
Lower half facets: The facets running from the girdle toward the culet; short in antique cuts, long in the modern round.

Questions to take with you

Is this a period stone, or a new diamond cut to antique proportions?
How does the culet read face-up: a neat circle, or a dark spot?
Is the girdle thin anywhere, and will the setting protect it?
Does the video show broad flashes in even light, not only under spotlights?
If the report calls it a cushion, do its table, crown, and culet match an old mine cut?