There is no player-obtainable raw gem named Fire Opal, so there are no craftable designs for them. However, there are a number of cut fire opals that drop from instance bosses in Heroic mode. There are also a few non-gem fire opal items.

Orange, match UI-EmptySocket-Yellow.png yellow or UI-EmptySocket-Red.png red sockets.
Name Effects Heroic Bosses
 [Champion's Fire Opal] +5 Strength +4 Defense Auchenai Crypts
 [Deadly Fire Opal] +5 Agility +4 Critical Arcatraz
 [Inscribed Fire Opal] +5 Strength +4 Critical Mana-Tombs
 [Lucent Fire Opal] +5 Agility +4 Resilience Old Hillsbrad
 [Polished Fire Opal] +4 Agility +5 Dodge Arcatraz
 [Potent Fire Opal] +5 Intellect +4 Critical Auchenai Crypts/Hellfire Ramparts
 [Reckless Fire Opal] +5 Intellect +4 Haste Shattered Halls/Steamvault
 [Resplendent Fire Opal] +5 Strength +4 Resilience Slave Pens
 [Splendid Fire Opal] +5 Parry +4 Resilience Underbog
 [Stalwart Fire Opal] +5 Parry +4 Dodge Black Morass/Sethekk Halls
 [Willful Fire Opal] +5 Intellect +4 Resilience Arcatraz

A sample of other items