Cut registry › Historic cuts › Old Mine
Historic cuts · The cushion antique
Chunky facets, big culet, soft square.
The old mine is the most sought-after antique cut and the weakest performer of the historic line. Both of those are true at once, and the second one is worth knowing before you buy.
The short version
An old mine cut diamond is a hand-cut antique brilliant with a soft square or cushion outline, a high crown, a small table, a large open culet and 58 facets.
It was the dominant diamond cut from roughly 1700 to the late 1800s, and it is the cut most often meant when a jeweller says a stone is antique.
Definition
Tolkowsky describes it at page 23 of Diamond Design and draws it at figure 11, where the triple cut has been made "more uniform" and "a somewhat rounder stone". That is the change: not more facets, but tidier ones on a less angular outline.
Its identifying features are consistent and easy to check. The outline is a soft-cornered square rather than a circle. The crown is high and the table small. The culet is large and open, so looking straight down you see a small dark circle at the centre where a modern stone comes to a point. Facets are broad and readable.
Every one was cut by hand and by eye, before mechanical bruting, so no two are alike. That is the appeal and it is also why generalised advice about old mines is close to useless: the stone in front of you is the only one that matters.
Two facet counts, and both are right. The historic count omits the girdle, because a hand-bruted stone had no faceted girdle to count. Our model resolves the girdle as real surfaces, so the census reads 74. Where a figure below depends on facet count, it is the measured number that produced it.
Proportions
Trade description on the left, our reconstruction from figure 11 on the right. Read the note under the table before reading the light figures.
| Measure | Commonly cited | Our reference stone | What it does |
|---|---|---|---|
| Outline | cushion / soft square | superellipse 2.70 | Rounder than the Peruzzi it followed. |
| Historic facets | 58 | 74 measured | The difference is the girdle. |
| Table | small by modern standards | 60.3% | Figure 11 shows a notably wide table for the era. |
| Depth | high crown, deep pavilion | 65.7% | Deep, and it shows in the figures. |
| Pavilion angle | steep | 44.4° | Steep enough to leak under a wide table. |
| Culet | large and open | modelled | The identifying feature, visible face-up. |
A caveat we would rather publish than bury. Figure 11 fixes the outline, the table and the uniformity of the facets, but it does not fix the profile. Our depths are therefore an interpolation, and the Global figure below is more sensitive to that build choice than any other cut in this section. Treat it as a careful reconstruction of the cut Tolkowsky drew, not as a survey of surviving stones, which vary enormously.
Light
Measured on the census that runs on every cut on this site: 3,200 rays face-up, 2,200 at 20° tilt, on exact facet geometry, against T57 as the standard.
| Material | Useful light | Leak | Fire | Scintillation | Global | vs the standard |
|---|---|---|---|---|---|---|
| Diamond | 58.82% | 31.96% | 72.42 | 80.69 | 74.31 | −14.29 |
| Moissanite | 59.51% | 28.68% | 84.91 | 80.69 | 77.37 | −12.45 |
| Cubic zirconia | 64.36% | 32.69% | 79.51 | 80.69 | 77.37 | −14.41 |
| T57 standard, diamond | 92.28% | 1.88% | 78.85 | 71.82 | 88.61 | 0.00 |
The old mine leaks 31.96% of the light entering it, the worst figure of the six historic cuts and against the modern standard’s 1.88%. Useful return falls to 58.82% and Global to 74.31, below the Peruzzi it descended from.
The cause is a wide table over a steep pavilion, which is exactly the combination that produces the effect the trade calls a nailhead: the centre of the stone goes dark while the edges stay bright. Figure 11’s 60.3% table sits over a 44.4° pavilion, and the light that enters the middle of the table exits through the bottom.
Tidying the facets did buy something. Fire rises to 72.42 from the Peruzzi’s 74-facet plan and the stone reads more evenly. It is a lateral move rather than an advance, and the honest way to describe the old mine in the lineage is as the moment cutters started caring about uniformity and paid for it in brightness.
Its Index tilt figure sits at the scale ceiling of 100. On a stone returning 58.82% face-up that means there was little left to lose. Do not read it as stability.
The nailhead, measured
Five equal bands across the outline, every returning ray binned by the point on the crown it leaves through. The old mine returns 54.3% across the centre against 66.9% at the edges. A modern round brilliant measures 99.1% against 98.1%, which is flat. That difference is the nailhead, and as far as we can find, this is the only place it is published as a number rather than described as a look.
Against the standard
Light return. 58.82% against the standard’s 92.28%, and 31.96% of leak against 1.88%. The gap is proportion, not facet count: both carry 58 historic facets.
Sparkle. 80.69 against 71.82. The old mine beats the modern standard here, for the same reason the Peruzzi does: sixteen measured girdle facets the knife-edge standard has not got.
Fire. 72.42 against 78.85, so the old mine loses this one too on our protocol. Its reputation for colour comes from how it is lit rather than from the figure: broad facets under a point source throw wide, well-separated flashes that a diffuse census does not reward.
Face-up size. An old mine of a given weight looks smaller than a modern brilliant of the same weight, because it carries far more of that weight in crown height and pavilion depth.
Character. Nothing measured here captures why people want one. Hand cutting, a large culet and broad readable facets give a slow, lazy flash that a modern brilliant does not produce, and no score on this site is a proxy for that.
The baseline for all of this is the round brilliant itself. Its facet plan is set out in the anatomy of a round brilliant, and the measured standard we compare against is T57, the stone Tolkowsky published in 1919.
Materials
In moissanite the old mine returns 59.51% for 77.37 Global, with fire at 84.91. Antique-style cuts are made in moissanite today precisely for this: the material’s dispersion suits an aesthetic built on large facets and colour rather than on white return.
In cubic zirconia it returns 64.36% for 77.37 Global, leaking 32.69%.
Compare all three for this cut in the Index.
Trade-offs
Questions
The questions buyers actually ask, answered in full. Where the answer is ours to prove, the figure is measured on the Index; where it is an established gemological fact, it is stated as one.
An old mine cut diamond is a hand-cut antique brilliant with a soft square or cushion outline, a high crown, a small table, a large open culet and 58 facets. It was the dominant diamond cut from roughly 1700 to the late 1800s, before mechanical bruting made truly round stones practical.
Outline and culet, mainly. An old mine has a soft square or cushion outline and a large open culet; an old european is genuinely round with a smaller culet. The difference in performance is large: we measure the old european at 87.82 Global against the old mine’s 74.31, because being round is worth more than any facet change in this lineage.
Because a wide table sits over a steep pavilion, so light entering the middle of the table exits through the bottom instead of returning. The trade calls it a nailhead. We measure it: the centre of our reconstruction returns 54.3% against 66.9% at the edges, where a modern round brilliant is flat.
The culet was left as a facet rather than closed to a point, partly to protect the fragile tip during handling and setting, and partly because closing it perfectly by hand was difficult. Face-up it reads as a small dark circle at the centre of the stone, and it is one of the clearest markers that a stone is genuinely antique.
That is a value judgement rather than a technical one, and the technical part is straightforward: recutting to modern proportions would raise light return substantially and cost weight. What it also destroys is the thing that makes the stone worth more than its carat weight. Most of the market now prices originality above brightness, which is the reverse of the twentieth-century view.
GIA will grade the stone but issues no cut grade for it, as with every fancy and antique shape. A report will typically describe it as a cushion or old mine brilliant and record colour, clarity, carat, symmetry and polish.
Usually yes, per carat, for good examples. Supply is fixed, since no new ones are being cut, and demand for genuine antique stones has risen. Old mines are generally regarded as scarcer than old europeans, which is reflected in the price.
Look for the combination rather than any single feature: a soft square outline with visible asymmetry, a small table under a high crown, broad readable facets, and a large open culet showing as a dark circle at the centre. Hand-cut stones are never perfectly symmetrical, and perfect symmetry in an apparently antique stone is a reason to ask questions.
It returns 58.82% of entering light against the standard’s 92.28% and leaks 31.96% against 1.88%. It beats the standard on scintillation, 80.69 against 71.82, and loses on fire, 72.42 against 78.85. Bright is not what it is for.
Its aesthetic is built on a small number of large facets throwing broad, well-separated flashes of colour, which a point source such as a candle or a low lamp shows off. Modern brilliants are optimised for many small returns under diffuse daylight, which is a different problem with a different answer.
Next
See the whole set on the historic cuts index, or the measured house and historic cuts in the cut registry.
Method
Monte-Carlo on exact facet geometry: 3,200 rays face-up plus 2,200 at 20° tilt, cosine-weighted from a 7° near-vertical cone. Useful light is what exits through the crown within 64° of vertical. The same protocol runs on every cut on this site, so the figures are comparable to each other.
They measure our reference geometry for the shape at the proportions listed above, not an average of stones on the market. A old mine cut to different proportions will read differently. Treat them as a like-for-like comparison between shapes, not as a grade for any individual stone.
Engine estimates, ±2 points, not lab-certified grades. We do not publish the Index symmetry axis on these pages: it scores facet regularity within each pavilion family, which is meaningful for a round brilliant and misleading for a shape whose pavilion is deliberately irregular.
80.69 here against the standard’s 71.82. The term is 100(1−e−n/45) on the count of facets that actually reach the surface, so it is a pure function of facet count and nothing else.