A fire opal, sometimes called girasol, is a distinctive type of opal found in Central and South America, which has a deep orange to red fiery color that has captivated jewelers for centuries. Unlike other opals, the fire opal is not actually opalescent, although it is composed of silicon dioxide, like other opals and quartzes. The color of the stone comes from iron oxide, a distinctively red-orange contaminant which frequently colors gemstones. The rich flamelike color dances with light when the stone is cut properly, but the inside of the stone is usually clear and free of inclusions.
Among the Amerindians, the fire opal was greatly valued and used in rituals and to ornament high placed members of society. The stone was known as quetzalitzlipyolliti, or the “stone of the bird of paradise,” because the Amerindians believed that the vivid color of the stone could only come from the fountain of paradise. The stones were observed by early European explorers, and by the 1850s, jewelry made with fire opals had become very popular in Europe. The traditional cut for the stone is a cabochon, a soft, round cut which minimizes damage to the stone and highlights the gorgeous color.
Mexico and Brazil are the two primary sources for the fire opal, although deposits of them do exist in other nations as well. The stone is so crucial to Mexican history and economy that it is the national stone of Mexico, and several beautiful specimens are kept in the National Museum of Mexico. The fire opal is mined in open-pit mines and exported all over the world, with some mines also cutting and polishing their raw stock while others send it to market uncut.
Like other opals, the fire opal is notoriously difficult to handle. The color can literally seem to flow out of the stone if it is cut wrong, and the stone is very brittle, making it easy to shatter catastrophically while being cut and polished. In addition, the fire opal needs to be kept in a pH neutral environment, and will be easily damaged by extreme heat, cold, or dampness. At the same time, the delicate balance of water inside the fire opal must be maintained: most jewelers agree that frequent wear helps to keep the opal moist, but opals should not be allowed to make contact with cosmetics and other substances that might cause them to cloud.