BRILLIANCE ← GUIDE

Proportions

Presets

Grade

— EXPECTED CUT AUDIT
—
Ideal scale—
Quick screen—

Measured

Light back—
Leaking—
Fire—
Contrast—
8-fold evenness—
ASET red—
ASET green—
ASET blue—
ASET black—
Total depth—
Crown height—
Pavilion depth—
Girdle—
Weight—
Spread—

Optical maps

came back out of the top leaked out of the bottom every path traced through this stone

Measuring…

light coming back
—
leaking out
—

THE CHISEL

—

Tap the stone to stand the chisel where you want it — that sets the index and the depth, and leaves the angle you dialled in alone. SPACE strikes. Z takes one back.

THE STONE

—

Light back—
Leaking—
Fire—
Contrast—
Weight—
Face-up size—
Total depth—
Facets—

Your strokes

Add a stone from the Bench to compare.
—
—
—
SCORE0 ROUGH1/3
WHAT THE LIGHT DOES
LIGHT RETURN—
LEAKAGE—
FIRE—
SCINTILLATION—
CARAT—
—
TABLE %
the flat top 57%
CROWN ANGLE
top slope 34.5°
PAVILION ANGLE
bottom slope 40.8°
GIRDLE
the rim 3.0%

BRILLIANCE

THE CUTTING BENCH · ENGAGEMENT RING GUIDE

A diamond is a piece of carbon with a very high refractive index and no opinions. Everything you find beautiful about one was decided by a cutter choosing angles.

1
Light enters the top and has to come back. Inside a diamond, any ray hitting a facet at more than 24.4° from its normal is reflected instead of escaping. That single number is why the shape works.
2
The pavilion is the mirror. Too shallow and light passes straight through the bottom — you get a window you can read a newspaper through. Too deep and it comes back out the side, dark under the table.
3
The crown makes fire. Steeper crown angles split white light into colour on the way out. Flatter crowns are brighter and duller at the same time.
4
And then there is weight. Leaving the stone deep keeps carats the market pays for. It is the oldest trade in the trade, and each rough here asks you to make it differently.
DRAG turn the stone   ← → pavilion   ↑ ↓ crown
[ ] table   ; ' girdle   L rays   I Tolkowsky   ENTER polish   R restart
1 learn   2 chisel   3 bench   · at the chisel, SPACE strikes and Z takes one back
← ENGAGEMENT RING GUIDE FONDSITE

—

—
—
← ENGAGEMENT RING GUIDE FONDSITE

BENCH CLOSED

—
—
KEEP READING Ring guidebooks Diamond database
← ENGAGEMENT RING GUIDE FONDSITE