DG-Rafaello Amethyst: Pros, Cons & Leakage

DG-Rafaello is a twelve-fold round whose pavilion curves in five tiers, each a little shallower than the last, from the girdle to the point. Our model has 145 facets and a quoted 40.0° pavilion, 59.0% deep.

In diamond it is one of our strongest rounds. In amethyst its light drops from 94 to 45, the largest fall of any modern round on our amethyst pages.

The quoted pavilion sits just under amethyst's guide minimum of 40.4°, and the lower tiers are shallower still.

Should amethyst be cut as DG-Rafaello? Pros and cons

Pros

Lighter than diamond 0.71 vs 0.94 ct
Much more sparkle than the T73 96 vs 80

Cons

A third of the diamond version's fire 26 vs 80
Over half the light leaks 55 vs 5
Under half the diamond version's light 45 vs 94

Compared with the T73 Round Brilliant in amethyst and with the DG-Rafaello 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-Rafaello in amethyst (white) against the T73 Round Brilliant in amethyst (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 amethyst: ahead on 3, level on 1, behind on 4.

Global61, the comparison 70, difference −9
Brilliance45, the comparison 72, difference −27
Fire26, the comparison 36, difference −10
Scintillation96, the comparison 80, difference +16
Spread101, the comparison 100, difference +1
Symmetry100, the comparison 100, difference 0
Shape-norm49, the comparison 77, difference −28
Tilt100, the comparison 80, difference +20

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 amethyst gains in DG-Rafaello

Lighter than diamond

0.71 ct at 6.5 mm, against 0.94 ct for the same cut in diamond (−25%)

A 6.5 mm DG-Rafaello is 0.71 ct in amethyst and 0.94 ct in diamond, the same volume in a less dense stone.

A DG-Rafaello 6.5 mm across, weighed from the model's measured volume and each stone's specific gravity.

Try it yourself: Weights in all seven gemstones on the DG-Rafaello page

Much more sparkle than the T73

Scintillation 96 against 80 for the T73 Round Brilliant in amethyst: 16 points higher

Twenty-four crown mains, twelve stars and five pavilion tiers break the face into far more facets than the T73's 73, and our scintillation score follows the facet plan.

DG-Rafaello · 145 facets · Scintillation 96

T73 Round Brilliant · 73 facets · Scintillation 80

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.

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

Why DG-Rafaello struggles in amethyst

A third of the diamond version's fire

Fire 26 against 80 for the DG-Rafaello in diamond: 54 points lower

Quartz's weak dispersion and a pavilion that lets most of the light go leave little to colour: 26, where the diamond version scores 80.

Dg-rafaello in amethyst face-up under a single bright light: a render from our simulator, its coloured flashes are the fire (score 26) — 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.

Dg-rafaello in diamond 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.

What helps: The Oval Cut Amethyst gives 69 in amethyst; among rounds, DG-Anteros Amethyst gives 54.

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

Over half the light leaks

Leakage 55 against 5 for the DG-Rafaello in diamond: 50 points higher

More than half the light in our census, 55%, goes out through the back; the diamond version loses 5%. Shallow lower tiers suit diamond's small critical angle; quartz needs steeper ones.

Dg-rafaello in amethyst tilted 0 degrees: Light Return map, 66% 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.

Dg-rafaello in amethyst tilted 10 degrees: Light Return map, 48% 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: We have no measurements of a re-angled DG-Rafaello, so we do not promise one. DG-M5 Amethyst, another twelve-fold round, leaks 15% in amethyst.

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

Under half the diamond version's light

Brilliance 45 against 94 for the DG-Rafaello in diamond: 49 points lower

Of the rounds on these amethyst pages, only the Old Single returns less.

Dg-rafaello in amethyst face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 45) — 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.

Dg-rafaello in diamond face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 94) — 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: DG-M5 Amethyst keeps a twelve-fold plan and returns 85 in amethyst.

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

Who a DG-Rafaello amethyst suits

We would not cut DG-Rafaello in amethyst for light. It is matched to diamond, and in quartz its face returns less than two-thirds of the T73's.

It suits a render or a collection that wants the twelve-fold sparkle in purple, or a cutter comparing one design across materials. Five pavilion tiers on a twelve-fold plan also make it a long project at the machine. Tilt reads 100, the top of the scale, but that is a steady share of little light.

For a twelve-fold round that works in quartz, DG-M5 Amethyst; for top sparkle with more light, DG-Vitruvio Amethyst. In diamond, see the DG-Rafaello Diamond.

DG-Rafaello Amethyst: questions

Is DG-Rafaello good for amethyst?

For sparkle only. Its face returns 45 where the T73 in quartz returns 72, and 55% of the light leaks.

Why does DG-Rafaello work in diamond but not in amethyst?

Diamond's critical angle is 24.4°, amethyst's about 40.4°, so pavilion tiers that hold light in diamond let it through in quartz: 55% leaks here, 5% in diamond.

DG-Rafaello or DG-M5 for amethyst?

DG-M5, by a wide margin: Brilliance 85 against 45, leakage 15% against 55%.

Get the DG-Rafaello Cut files

6 formatsMillimetresWatertight

DG-Rafaello Cut 3D files

The DG-Rafaello Cut as exact geometry: 145 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

DG-Rafaello Cut cutting files

The DG-Rafaello Cut as a faceting design: 121 + 24 girdles = 145 facets, 96 index, 12-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

Amethyst: optical properties and the top ten cuts · The DG-Rafaello: specifications, model and files

DG-Rafaello Amethyst: fine sparkle, from a pavilion drawn for diamond