T105 Round Brilliant Cubic Zirconia: the 1919 round with extra facets and finer sparkle

Brilliance 98 · Fire 85 · Scintillation 90 · in our census, where the T73 scores 98 · 87 · 80 in cubic zirconia

Forty-eight extra facets on the 1919 plan: in CZ they buy finer sparkle and cost no light.

See it in the simulatorGet the files
The T105 Round Brilliant in cubic zirconia, rendered at an angle in our 3D Gemstone Simulator under studio light
Rendered in our 3D Gemstone Simulator from the T105 Round Brilliant model, 1.00 ct, studio light.

T105 Round Brilliant Cubic Zirconia

The T105 keeps the main angles of the 1919 round and divides it further: eight star halves on the crown, and three rows of lower halves on the pavilion where the T57 has one. There is no girdle band; crown and pavilion meet at a knife edge. Measured, the model is 59.3% deep, and its pavilion mains keep the 1919 angle of 40.75°.

In CZ its light matches the T73's, 98 each, and so does its leakage. Its fire is 85 against the T73's 87, too close to count. Sparkle is where it pulls ahead.

Is a T105 round a good choice for CZ? Pros and cons

Pros

Cons

Compared with the T73 Round Brilliant in cubic zirconia and with the T105 Round Brilliant 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 T105 Round Brilliant 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.

Performance wheel: T105 Round Brilliant in cubic zirconia, against the T73 Round Brilliant in cubic zirconia as an outline. Solid white marks where it reaches further, hatching where it falls short. The scores are listed below.50100Global0Brilliance0Fire−2Scintillation+10Spread+1Symmetry0Shape-norm0Tilt0

Against the T73 Round Brilliant in cubic zirconia: ahead on 2, level on 5, behind on 1.

  • Global93, the comparison 93, difference 0
  • Brilliance98, the comparison 98, difference 0
  • Fire85, the comparison 87, difference −2
  • Scintillation90, the comparison 80, difference +10
  • Spread101, the comparison 100, difference +1
  • Symmetry100, the comparison 100, difference 0
  • Shape-norm106, the comparison 106, difference 0
  • Tilt87, the comparison 87, difference 0
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 the T105 gives cubic zirconia

Finer sparkle than the T73

Scintillation 90 against 80 for the T73 Round Brilliant in cubic zirconia: 10 points higher

Star halves and three tiers of lower halves split the light into smaller pieces: 105 facets against 73. Our scintillation score tracks that, and the crown diagram shows the added lines.

T105 Round Brilliant · 105 facets · Scintillation 90

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

More fire than the T105 in diamond

Fire 85 against 77 for the T105 Round Brilliant in diamond: 8 points higher

Diamond and CZ share the plan here; what differs is how strongly each stone spreads light into colour, 0.060 for CZ and 0.044 for diamond. The CZ render shows the result.

T105 round brilliant in cubic zirconia face-up under a single bright light: a render from our simulator, its coloured flashes are the fire (score 85)

T105 Round Brilliant in cubic zirconia · Fire 85

T105 round brilliant in diamond face-up under a single bright light: a render from our simulator, its coloured flashes are the fire (score 77)

T105 Round Brilliant in diamond · Fire 77

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

A little more light than in diamond

Brilliance 98 against 95 for the T105 Round Brilliant in diamond: 3 points higher

Brilliance 98 here against 95 for the same plan in diamond. Real by our margins, and small next to the gaps on most CZ pages.

T105 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)

T105 Round Brilliant in cubic zirconia · Brilliance 98

T105 round brilliant in diamond face-up Light Return map: red, green and blue show where the light returns from, grey shows where it leaks (Brilliance 95)

T105 Round Brilliant in diamond · Brilliance 95

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.

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

The catch with a T105 CZ

Much heavier than diamond

1.51 ct at 6.5 mm, against 0.92 ct for the same cut in diamond (+65%)

Knife edge or not, the material sets the weight: a CZ is about 65% heavier than a diamond of the same outline. The T105's shallow 59.3% depth makes it one of the lighter rounds for its width.

Cubic Zirconia1.51 ctDiamond0.92 ct
A T105 Round Brilliant 6.5 mm across, weighed from the model's measured volume and each stone's specific gravity.

What helps: Choose by width. At 6.5 mm a T105 CZ weighs 1.51 ct.

Try it yourself: Weights in all seven gemstones on the T105 Round Brilliant page

Who a T105 CZ suits

Choose the T105 in CZ for a round with more sparkle than the T73 and the same light. Keep the knife edge protected, in a bezel or behind a rim.

For a girdle a setter can seat, the T73 Round Brilliant Cubic Zirconia. For finer sparkle still at the same light, DG-Vitruvio Cubic Zirconia scores 98.

For cutters, the T105 is the T57 with extra tiers of lower halves: a step up in meet-point practice, and CZ is a forgiving stone to take it on.

Against the diamond version, CZ gives a little more light and more fire, with the same sparkle and the same steadiness when tilted (87 in both stones); only the weight goes against it.

T105 Round Brilliant Cubic Zirconia: questions

Is the T105 brighter than the T73 in cubic zirconia?

No, level: Brilliance 98 for both. The T105 sparkles more, 90 against 80.

T105 or T57 for a CZ?

Equal light (98 against 98), and more sparkle for the T105: 90 against 72.

Does the T105 have a girdle?

No. Crown and pavilion meet at a knife edge, as on the T57; the T73 adds a sixteen-facet girdle band.

What does a 6.5 mm T105 CZ weigh?

1.51 ct, where a diamond of the same width is 0.92 ct.

Get the T105 Round Brilliant Cut files

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T105 Round Brilliant Cut 3D files

The T105 Round Brilliant Cut as exact geometry: 105 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

T105 Round Brilliant Cut cutting files

The T105 Round Brilliant Cut as a faceting design: 105 facets, 96 index, 8-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 T105 Round Brilliant: specifications, model and files

Other cuts in cubic zirconia

The T105 Round Brilliant in other gemstones