The Guide to Old Mine Cut Diamonds

Cutters shaped these stones in the 1700s and 1800s with hand tools and their own eyes, long before modern cutting machines existed. The result is a cushion-shaped diamond with a small table, a tall crown and broad facets, usually 58 of them. At the bottom, the point was polished flat into a small facet called the culet, and you can often see it face-up as a tiny circle.

No two match. Some sit square and others stretch into a gentle rectangle, and most carry a little asymmetry. That's the point. "Modern windows are judged by how perfectly flat and efficient they are," Ken says. "Antique glass is appreciated for something entirely different. The glass may be wavy and imperfect, and those imperfections are part of its beauty, but you still don't want it chipped or broken." If an old mine were cut to perfect modern symmetry, it would start to look like a modern brilliant and lose the character people come to it for.

Natural old mines. Most come from estate jewelry. We source them through trusted dealers who specialize in antique stones, so each one is a diamond that has already lived a life and gets a new one in your ring.

Lab-grown old mines. These are new diamonds, cut to look like old mines. They're a lovely way to get the look at a lower price, though they carry no history of their own. Our standard lab-grown old mines are listed in our loose diamond search tool. When a client wants something the market doesn't offer, we custom cut it with one of two suppliers we've trusted for years.

The old mine cut diamond is often compared to, and even confused with, the old European cut diamond. They both carry the same unique, antique appeal as they originate from roughly the same era. The old mine cut diamond is over 100 years older than the old European cut. The popularization of the old mine cut occurred in the early 18th century and the European cut became common fairly late in the 19th century.

While they’re of the same era, they have key differences to their cuts. The old European cut has a much rounder outline, very similar to the modern round brilliant cut diamond. The outline of the old mine cut diamond has more in common with the modern cushion cut. Their culets also vary in size and visibility. Both diamond cuts will have a visible culet, but the culet of the old mine diamond is much larger and you can easily see it through the table with the naked eye.

The proportions of each are slightly different as well due to the nature of their differing cut styles. The old mine cut is slightly shallower while the old European cut has a heavier crown and slightly smaller table. And even though each has 58 facets and showcases a soft brilliance and warmth, their fire – how they show color and contrast patterns – will display differently.

When compared to each other, old European cut diamonds often carry an additional level of appeal because they typically have better symmetry and strike a better balance between the old and new aesthetic. Excellent examples of either cut type are typically very hard to find, and any diamond should be viewed individually since the qualities vary greatly from stone to stone.

Ken's quick test: "An old mine is a cushion shape, and an old euro is round. Old mines came first, so they're more obviously imperfect. A modern 'antique-style' cushion usually has smaller facets and much better symmetry than a genuine old mine."

The GIA doesn't give old mines a grade, so shopping for an old mine cut diamond isn’t as straightforward as shopping for a modern diamond cut. Because these diamonds are antiques and no longer produced, supply is extremely limited and only a handful of jewelers will offer or work with old mine diamonds.

As always, focus on what you like and prefer in the look of a diamond. If you’re interested in old mine diamonds, then you’re already swayed toward a warm, romantic, sentimental engagement ring style, so embrace that fully. The modern grading system doesn’t account for the beauty and appeal that rests in the slight imperfections and eccentricities of each diamond.

Focus on what looks attractive to your eye when choosing an old mine diamond. Look for good symmetry with a length-to-width ratio below 1.1 for the most pleasing shape. And observe the diamond from different angles to make sure there are no noticeable bulges – this could be a sign that the cutter placed too much priority on maximizing weight instead of a quality cut.

Here are Ken's tips on what he looks for in an old mine diamond:

Faceting comes first. "I want a stone that twinkles, with broad, chunky facets that give it that unmistakable old-world charm."

Imperfect, not messy. Some irregularity is welcome. Ken passes on a stone when the faceting looks chaotic, the shape is noticeably lopsided, or the light doesn't make a pleasing pattern. "There's a difference between charmingly imperfect and simply messy."

A visible culet, within reason. Ken likes seeing the small circle at the center, though not a very large one. How much lopsidedness is too much is personal. "Beauty is truly in the eye of the beholder. I just know I love something when I see it."

Color. Natural old mines turn up across the whole range, from D to U. Ken's sweet spot is G to K, where a hint of warmth adds old-world charm. Below about L or M, the color starts to show too much. Lab-grown old mines are rarely available below G.

Champagne and cognac. Warm brown tones had a moment this year. Those stones were so hard to find that we began custom cutting them for clients.

Lastly, photos tend to flatten these stones. For our clients, we share 360-degree videos of each diamond, which show how the facets move. You're also welcome to book an appointment at our New York studio and see the stones in person.

Currently prices for our loose old mine lab diamonds weighing from 2.2ct to 2.5cts range from $2,300 to $3,200 (prices as of late 2026).

Old mines need no special handling once they're set. Unless a stone is chipped, it's as strong as a modern diamond, and often stronger, since many old mines have thick to very thick girdles (the edge around the widest part).

An uneven outline does ask more of our setters, so we plan for it when we build the ring's 3D model. If we find a chip, we recommend repairing it before setting. A cutter removes the damaged area and rebalances the stone. "It's incredible how little an experienced cutter needs to shave off to bring the diamond back to beautiful form," Ken says. The stone ends up very slightly smaller and lighter.

The design doesn't change how Ken chooses a stone, apart from shape: square or rectangular.

Taylor Swift's engagement ring, revealed in August 2025, set an elongated old mine cut in yellow gold. Our old mine requests rose sharply afterward. Nine in ten asked for champagne or cognac color in an elongated cushion shape. Most were extremely hard to source, which is how we started custom cutting.

We've found that the couples who choose old mines want something unique, with character and old-world charm.