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Judging Brilliance,
Fire and Scintillation
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Brilliance - Diamonds that appear
strong pink/red through the Ideal-Scope
have the best light return. The less
leakage the better, but brilliance
is not only about light return. Contrast
has a role to play too.
The dark 8 rayed star should not be
too thick; too much darkness in a diamond
through the Ideal-Scope means less light
is returned, just like leakage. (Thick
stars occur when pavilion lower girdle
facets that are too short). But if the
star is too thin then the diamond will
lack contrast and scintillation and
it will have less fire.
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THICK
STAR
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AVERAGE
STAR
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THIN
STAR
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PROS
- increased fire
CONS
- reduced light return and scintillation |
PROS
- balanced contrast, scintillation
and fire
CONS
- none |
PROS
- increased light return
CONS
- reduced fire. contrast and scintillation |
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Fire
- Diamonds with thick dark stars are
usually more firey. However there is
a trade off when it comes to light return.
Diamonds that are a little to deep,
with leakage through the table region,
can display more fire if they are set
so that light can get in from behind. |
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Scintillation
- Thick dark prominent stars reduce
light return but as discussed in the
newsletter,
some contrast is needed to enhance our
perception of brilliance as the diamond
is rocked from side to side. The dark
/ bright alternating contrast creates
a 'bang bang' sparkle effect. Small
bits of leakage near the girdle often
contribute to that contrast.
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| Ideal
Cut with excellent scintillation
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Poor
cut with poor scintillation |
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A
checker board is half as bright as a
sheet of white paper, but when you move
the two, the scintillating effect of
the checker board is far more eye catching.
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