If you've started looking at antique engagement rings, you'll have seen two names again and again: the old mine cut and the old European cut. Both were cut by hand, long before computers and modern machinery, and both have a softer, more romantic sparkle than today's diamonds. But they're not the same, and once you know what to look for, you'll spot the difference in seconds.

I've been buying antique diamonds for over fifteen years, and these are the two cuts I'm asked about most. Here's what makes each one special.

The short answer

An old mine cut is squarish, with softly rounded corners, like a cushion. An old European cut is round. Both have a small table, a tall crown and a little open window at the bottom of the stone, called the culet, which you can often see as a tiny circle when you look straight down.

	Old mine cut	Old European cut
Shape	Cushion: squarish with rounded corners	Round
Era	Roughly 1700s to 1890s: Georgian and Victorian	Roughly 1880s to 1930s: late Victorian, Edwardian and Art Deco
Culet	Large, often clearly visible	Smaller, but usually still visible
Symmetry	Charmingly irregular; no two alike	More even and balanced
Sparkle	Broad, chunky flashes of light	Bright flashes with a little more brilliance

The old mine cut

The old mine cut is the ancestor of the modern brilliant. It takes its name from the "old mines" of India and, from the 1720s, Brazil, where most diamonds came from before the great South African discoveries of the 1870s.

Each stone was cut by eye, following the natural shape of the rough crystal to keep as much weight as possible. That's why old mine cuts are cushion-shaped rather than perfectly round, and why every one is slightly different. They have a small table on top, a high crown and a deep pavilion, with a large culet at the base.

The result is a diamond made for candlelight. Rather than the glittery "disco ball" effect of a modern diamond, an old mine cut gives you big, slow flashes of light and color as it moves. You'll find them in Georgian and Victorian jewelry, from cluster rings to five-stone rings.

The old European cut

By the 1870s, two things had changed. Huge new diamond deposits were found in South Africa, and new machinery allowed cutters to shape diamonds into rounder outlines. The old European cut was born.

It keeps much of the old mine cut's character, with the small table, tall crown and open culet, but in a round, more symmetrical form. That balance gives it a touch more brilliance, while it still has the soft, glowing quality modern stones lack. The old European cut was the diamond of the late Victorian, Edwardian and Art Deco eras, and it led directly to the modern round brilliant, whose proportions were set out in 1919.

How to tell them apart

You don't need a loupe to start. Look at three things:

• The outline. Squarish with rounded corners points to an old mine cut. A true circle points to an old European cut.
• The culet. Look straight down through the table. A small dark or light circle in the center means an open culet, which both cuts have. A large, obvious one leans towards an old mine cut.
• The symmetry. If the facets look a little uneven and handmade, it's likely an old mine cut. If they look neat and even, it's more likely an old European cut.

There's also a halfway house: the transitional cut of the 1930s to 1950s, which sits between the old European cut and the modern round brilliant. And you'll sometimes find both old cuts in the same ring, as in our Victorian 0.70 carat engagement ring.

Which should you choose?

There's no right answer, only the one that speaks to you. In my experience:

• Choose an old mine cut if you love something soft, romantic and unmistakably antique. Its cushion shape looks beautiful in Georgian and Victorian settings and in cluster rings.
• Choose an old European cut if you want the look of a classic round solitaire with more character than a modern stone. It sits perfectly in Edwardian platinum and Art Deco designs.

What to know before you buy

• Color. Many old cut diamonds are slightly warmer in color than modern stones, often in the near-colorless to faint range. That warmth is part of their charm and suits yellow gold beautifully.
• Grading. Laboratories grade old cuts for color and clarity, but they usually don't give a cut grade, because modern cut standards don't apply. Where a diamond has a report, we'll always share it.
• Condition. After a century or more of wear, check for chips around the girdle, the thin edge of the stone. Every diamond we sell is examined before it's listed, and its condition is described honestly.
• Rarity. Many old cut diamonds were recut into modern shapes during the twentieth century, so good original examples are becoming harder to find.

See them for yourself

Photographs can only show so much of an old cut diamond's sparkle. If you'd like to see one properly, book a video consultation and I'll show you rings up close, in daylight and on the hand.

Browse our antique diamond rings and antique engagement rings, or get in touch if you're searching for something specific.

Tiffany is the founder of Mayveda, a Fellow of the Gemmological Association of Great Britain (Gem-A) and a GIA-certified diamond grader.