Fire Opal

Color:   Red to orange to gold, fire opal has an almost dayglo intensity of color
Gem Family:   Fire opal is a vividly colored transparent variety of opal, with or without play of color.
Source:   Fire Opal is mined in Mexico in the states of Queretaro, Hidalgo, Guerrero, Michoacan, Julisio, Chihuahua and San Luis Potosi. The mines of Queretaro are the most significant and have been mined since 1835. Small pebbles of fire opal are found in lava flows rich in silica.
Clarity:   Transparent to translucent
Size Range:   0.5 carat to 5 carats. Rare gems have been found that are up to 50 carats in size.
Shapes Available:   Although fire opal is traditionally cut in cabochons, like other types of opal, fine qualities can be faceted to add brilliance to the vivid color. Ovals, trillions, cushions, and rounds are available.
Enhancement:   Fire opal is not treated: the color is natural, exactly as it is found in the earth.
Lore & History:   Mexico, land of the sun, has temples built to honor the firey orb that rules our days. Aztec sun temples are as much what draws travelers to Mexico as modern sun worshipping on the beaches of Cancun. Unique to Mexico, fire opal has been treasured since the time of the Aztecs. Its fiery color is unique in the gem world for its vivid intensity.
Toughness & Hardness:   The hardness of fire opal is 5.5 on the Mohs scale, similar to tanzanite.
Care & Cleaning:   Most people know that opal is one of the softer gemstones and requires some extra care by the wearer. Fire opal is the same. Don't wear it when you know you will be doing hard physical work. If they are hit hard, they can chip. To clean fire opal, use warm water and detergent. Scrub with a soft brush and rinse with warm water. It is not necessary to store your fire opal in water or oil when not wearing it. Do store it separately in a soft pouch where it won't get damaged or scratched by other jewelry.
Special Characteristics:   Unlike other opals, most fire opal is faceted to add brilliance to its firey color. Fire opal sometimes displays play of color, the shifting spectrum of colors that makes Australian opal one of the most colorful gems. The contrast of shifting rainbow colors against the bright orange of fire opal's body color is almost psychedelic. Fire opal that displays play of color is cut into cabochon shapes.