Old Mine Cut Cubic Zirconia: Pros, Cons & Fire

In CZ, as in diamond, the Old Mine's wide 60.3% table and steep pavilion let a third of the light out of the back. CZ adds fire: 80 against 72 for the diamond version.

Its brilliance even edges past the diamond version, 64 against 59, but the T73 in CZ returns far more, and that larger gap is the one we count.

Like the Old European, the Old Mine returns a little more light in CZ than in diamond. It is still a dim stone beside the T73, and it shares the diamond version's leak almost exactly: 33% here, 32% there.

It sparkles as much as a modern round, scintillation 81 against 80: the facet count is close, the light behind it is not.

Is CZ good in an Old Mine cut? Pros and cons

Pros

More fire than in diamond 80 vs 72

Cons

Far heavier than diamond 1.99 vs 1.21 ct
Much less light than the T73 in CZ 64 vs 98
A third of the light leaks 33 vs 1
A less regular pavilion 90 vs 100

Compared with the T73 Round Brilliant in cubic zirconia and with the Old Mine Cut in diamond. A difference counts from 3 points (Brilliance, Fire, Tilt, Leakage), 5 (Scintillation, Symmetry), 2 (Spread) or 5% (weight); Tilt counts as a pro only for a stone within 5 points of the brilliance it is compared with. How we measure.

All eight scores against the T73

At a glance: the Old Mine Cut in cubic zirconia (white) against the T73 Round Brilliant in cubic zirconia (dashed): solid white where it reaches further, hatched where it falls short. Each pro and con is explained, with pictures, below.

Against the T73 Round Brilliant in cubic zirconia: ahead on 2, behind on 6.

Global77, the comparison 93, difference −16
Brilliance64, the comparison 98, difference −34
Fire80, the comparison 87, difference −7
Scintillation81, the comparison 80, difference +1
Spread98, the comparison 100, difference −2
Symmetry90, the comparison 100, difference −10
Shape-norm101, the comparison 106, difference −5
Tilt99, the comparison 87, difference +12

Face-up light census, a different measure from the Cut Grading Tool; Spread and Shape-norm above 100 sit on the ring.

Open it in the Cut Performance Wheel

What cubic zirconia gains in an Old Mine cut

More fire than in diamond

Fire 80 against 72 for the Old Mine Cut in diamond: 8 points higher

Higher dispersion, the same broad facets: more colour in the CZ render.

Old mine cut in cubic zirconia face-up under a single bright light: a render from our simulator, its coloured flashes are the fire (score 80) — Look at the coloured flashes: those are fire. Same light, same size, same face-up angle; rendered by our 3D Gemstone Simulator from each cut's own model.

Old mine cut in diamond face-up under a single bright light: a render from our simulator, its coloured flashes are the fire (score 72) — Look at the coloured flashes: those are fire. Same light, same size, same face-up angle; rendered by our 3D Gemstone Simulator from each cut's own model.

Try it yourself: See the fire in the 3D Gemstone Simulator

The catch with an Old Mine CZ

Far heavier than diamond

1.99 ct at 6.5 mm, against 1.21 ct for the same cut in diamond (+65%)

Density, not the cut, sets this: CZ's specific gravity is about 5.8 against diamond's 3.52.

A Old Mine Cut 6.5 mm across, weighed from the model's measured volume and each stone's specific gravity.

What helps: None in the cut; CZ is dense. A 6.5 mm stone is 1.99 ct.

Try it yourself: Weights in all seven gemstones on the Old Mine Cut page

Much less light than the T73 in CZ

Brilliance 64 against 98 for the T73 Round Brilliant in cubic zirconia: 34 points lower

The face-up map has grey down both flanks of the cushion; the T73's is nearly all colour.

Old mine cut in cubic zirconia face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 64) — Red, green and blue = light returning to the eye; grey = light leaving through the pavilion. This is the head-on view; the Brilliance score averages a wider cone of light, so the score can differ from what one picture shows.

T73 round brilliant in cubic zirconia face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 98) — Red, green and blue = light returning to the eye; grey = light leaving through the pavilion. This is the head-on view; the Brilliance score averages a wider cone of light, so the score can differ from what one picture shows.

What helps: In CZ the Peruzzi Cut Cubic Zirconia returns 67, the modern Cushion Cut 88.

Try it yourself: Open this Light Return map in the simulator

A third of the light leaks

Leakage 33 against 1 for the T73 Round Brilliant in cubic zirconia: 32 points higher

33% in our census against 1% for the T73. The strip shows the grey thinning as it tips, without clearing.

Old mine cut in cubic zirconia tilted 0 degrees: Light Return map, 39% of the face leaking — Each frame is the Light Return map with the stone tilted away from you by the angle shown; grey is light leaving through the pavilion. The share under each frame is that picture's own.

Old mine cut in cubic zirconia tilted 10 degrees: Light Return map, 29% of the face leaking — Each frame is the Light Return map with the stone tilted away from you by the angle shown; grey is light leaving through the pavilion. The share under each frame is that picture's own.

What helps: The Cushion Cut leaks 7% in CZ.

Try it yourself: Tilt it yourself in the simulator's light map

A less regular pavilion

Symmetry 90 against 100 for the T73 Round Brilliant in cubic zirconia: 10 points lower

Symmetry 90: the pavilion facets vary more than a modern round's.

Old Mine Cut · 74 facets · Symmetry 90

T73 Round Brilliant · 73 facets · Symmetry 100

Symmetry scores how regular the pavilion facets are within the design. Compare how evenly the facets repeat around each pavilion. Drawn from each cut's own model.

What helps: This is the design. The Old European Cut scores 100.

Try it yourself: Compare the Symmetry spoke in the Cut Performance Wheel

Who an Old Mine CZ suits

Choose it to practise the old mine cut or to mock up an antique setting cheaply.

For light, the modern Cushion Cut; for an antique look that stays bright in CZ, the Old European Cut Cubic Zirconia.

For a cutter, the steep 43.0° crown and 44.38° pavilion set this result. The pavilion is already above CZ's guide minimum of 38.1°, so steepening it further is not what the data supports.

On a practice wheel, the Old Mine's 74 facets are a fair test of meet-point accuracy before cutting a costlier stone.

Old Mine Cut Cubic Zirconia: questions

Is Old Mine cut CZ bright?

Dim beside a modern round: Brilliance 64 against 98 for the T73 in CZ, with 33% leakage.

Does Old Mine cut CZ have more fire than diamond?

Yes: Fire 80 against 72.

What does a 6.5 mm Old Mine CZ weigh?

About 1.99 ct, from the model's volume and CZ's specific gravity of about 5.8.

Old Mine CZ or modern cushion CZ?

The modern Cushion returns 88 in CZ and leaks 7%; the Old Mine 64 and 33%.

Get the Old Mine Cut files

6 formatsMillimetresWatertight

Old Mine Cut 3D files

The Old Mine Cut as exact geometry: 74 planar facets, real-world scale, ready for CAD, rendering, printing and casting.

STEPExact faceted solid for CAD
3DMRhino, closed mesh on its own layer
STLWatertight mesh for printing and casting
OBJMesh for modelling and rendering
FBXBlender, 3ds Max, Maya, Cinema 4D, Unity, Unreal
GLBWeb, AR and quick previews

€9.99 · Personal useBuy the 3D files

GemCad96 index

Old Mine Cut cutting files

The Old Mine Cut as a faceting design: 58 + 16 girdles = 74 facets, 96 index, 4-fold mirror-image symmetry, ready for the machine.

.ascGemCad design file, 96 index gear
.csvTier table: angles, indices and cutting order
DiagramPrintable faceting diagram

€9.99 · Personal useBuy the cutting files

Questions before you buy? Email us.

More gemstones and cuts

Cubic Zirconia: optical properties and the top ten cuts · The Old Mine Cut: specifications, model and files

Old Mine Cut Cubic Zirconia: more fire than the diamond version, and as much leakage