Mexican fire opal choker / Necklace. Choker measures approx. 14.5” with 1” extender. SHOP this Mexican fire opal choker Necklace choker for EVERYDAY & the BEACH! The Mexican fire opal has many positive attributes to bring to the life of its wearer. Mentally, the fire opal is said to be a wonderful stone for those people who are shy and lack self-confidence.