feux

CONT: Si la table est trop grande, le diamant n'aura pas autant de scintillement ou de feux (étincelles aux couleurs de l'arc-en-ciel, qu'on désigne plus scientifiquement par le terme dispersion).

CONT: Fire is the trade term used in jewellery and gemmology for the refraction of white light causing the display of spectrum colours and scintillation on the stone.
CONT: If [the table] is too large, the diamond won't have much sparkle or fire (flashes of rainbow colors, which are technically referred to as dispersion).