Rendered in our 3D Gemstone Simulator from the DG-Vitruvio model, 1.00 ct, studio light.
DG-Vitruvio Sapphire
DG-Vitruvio keeps the proportions of the 1919 round and does all its extra work at the girdle, where a band of 96 small facets takes the place of the T73's sixteen. In our model that comes to 153 facets on a 40.75° pavilion, with the stone 61.9% deep.
In sapphire that leaves Brilliance where the T73 has it, 94 against 94, and lifts the score for sparkle by a wide margin. What the girdle cannot touch is the material. Blue, pink or colourless, a sapphire splits white light weakly, and it lets light go sooner than diamond once the stone leaves face-up.
Is DG-Vitruvio a good cut for a sapphire? Pros and cons
Compared with the T73 Round Brilliant in sapphire and with the DG-Vitruvio 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 DG-Vitruvio in sapphire (white) against the T73 Round Brilliant in sapphire (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 sapphire: ahead on 2, level on 5, behind on 1.
Global81, the comparison 79, difference +2
Brilliance94, the comparison 94, difference 0
Fire37, the comparison 37, difference 0
Scintillation98, the comparison 80, difference +18
Spread100, the comparison 100, difference 0
Symmetry100, the comparison 100, difference 0
Shape-norm101, the comparison 102, difference −1
Tilt75, the comparison 75, difference 0
Face-up light census, a different measure from the Cut Grading Tool; Spread and Shape-norm above 100 sit on the ring.
Scintillation 98 against 80 for the T73 Round Brilliant in sapphire: 18 points higher
Our scintillation score follows the facet plan, and 153 facets against the T73's 73 put DG-Vitruvio near the top of our sapphire scale. The added facets all sit in the girdle band, so the extra sparkle gathers round the rim rather than across the table.
Scintillation follows the number of facets: more facets, more and smaller flashes as the stone moves. Count the facets in each crown. Drawn from each cut's own model.
Fire 37 against 79 for the DG-Vitruvio in diamond: 42 points lower
The cut is identical in both stones; only the dispersion differs, 0.018 for corundum against 0.044. A finer girdle cannot make colour that the material never separates.
DG-Vitruvio in sapphire · Fire 37
DG-Vitruvio in diamond · Fire 79
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.
What helps: No round moves this far in sapphire. The most fire among our sapphire rounds is DG-Anteros Sapphire's 43; the Oval Cut Sapphire reaches 74, with much less light.
Tilt 75 against 93 for the DG-Vitruvio in diamond: 18 points lower
Tilted 20°, it keeps 75 of its face-up light, where the diamond keeps 93. Sapphire's critical angle of 34.6°, against 24.4° in diamond, gives light more ways out once the stone tips.
DG-Vitruvio in sapphire · Tilt 75
0° · 1% leak
10° · 11% leak
20° · 29% leak
30° · 30% leak
DG-Vitruvio in diamond · Tilt 93
0° · 4% leak
10° · 2% leak
20° · 9% leak
30° · 15% leak
Tilt is how much of its own face-up light a stone keeps when tilted. 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: Of our modern rounds in sapphire, DG-Miliano Sapphire keeps the most light when tipped, 83, and sparkles just as finely: 98.
Leakage 6 against 2 for the DG-Vitruvio in diamond: 4 points higher
6% of the light in our census escapes through the pavilion, against 2% for this cut in diamond and 5% for the T73 in sapphire. The girdle work changes the sparkle, not this.
DG-Vitruvio in sapphire · Leakage 6
0° · 1% leak
10° · 11% leak
20° · 29% leak
30° · 30% leak
DG-Vitruvio in diamond · Leakage 2
0° · 4% leak
10° · 2% leak
20° · 9% leak
30° · 15% leak
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: Steepening is not the remedy: the pavilion, at 40.75°, already clears sapphire's 36.4° guide minimum. DG-M5 Sapphire leaks 0% in sapphire.
DG-Vitruvio suits a round sapphire where sparkle is the priority and the light should match the T73. In a colourless or pale stone the finer flashes are what the eye picks up; in a deep, inky blue more of that detail may disappear into the colour.
The most light we measure in sapphire comes from DG-M5 Sapphire, 100. For a round that holds its light better when it tips, DG-Miliano Sapphire. If coloured flashes are the point, no round delivers them in corundum; the Oval Cut Sapphire comes closest.
DG-Vitruvio Sapphire: questions
Is DG-Vitruvio a good cut for sapphire?
For sparkle, yes: Scintillation 98 against 80 for the T73 in sapphire, with Brilliance level at 94. Fire stays low at 37.
DG-Vitruvio or T73 for a sapphire?
Their light and fire match: Brilliance 94 against 94, Fire 37 against 37. DG-Vitruvio adds sparkle; the T73 has 73 facets to cut instead of 153.
What does a 6.5 mm DG-Vitruvio sapphire weigh?
About 1.16 ct, where a diamond of that width weighs 1.02 ct.
Is a DG-Vitruvio sapphire hard enough for a daily ring?
Sapphire is 9 on the Mohs scale, behind only diamond and moissanite among the stones on this site, and it is a common choice for rings worn every day. A setting that covers the faceted girdle protects its fine edges.
Get the DG-Vitruvio Cut files
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DG-Vitruvio Cut 3D files
The DG-Vitruvio Cut as exact geometry: 265 planar facets, real-world scale, ready for CAD,
rendering, printing and casting.
