So even though Fire Opals are from outside Australia we thought these five tips would be handy. They are most commonly found in Maxico and generally embedded in volcanic rock formations near the Yucatan Peninsula in Southern Mexico. Stability Fire opals are extremely fragile in nature, and unfortunately can be prone to crack within just a few months of wear. Check if the fire opal retailer keeps the stone for at least a year before selling it, and if they offer a guarantee against natural cracks and fissures. Most reputable dealers do! Clarity Look closely at the brightness or clarity o...