Here is a very fine Mexican Fire Opal set in a 7x9 Turk's Head bezel made with 18K yellow gold. The dimensions of the piece, with the setting, are about 0.6" tall by 0.5" wide.
Opal with seven-lead nine-bight Turk's Head setting.
$4,500
To see how it looks with light striking it at different angles, see the following images: