Mexican Fire Opal

Fire opal refers to the variety of transparent red, orange or orangy-red opal usually lacking play-of-color. Fire opal is cut en cabochon as well as faceted. The source for this gem material is Mexico, hence the name.

Edwardian Faceted Fire Opal Brooch.
Photo courtesy of Sotheby’s.

Gemological Information for Mexican Fire Opal

Color:Red, Orange, Orangy-Red
Crystal Structure:Amorphous
Refractive Index:1.43-1.47
Durability:Relatively Poor
Similar Stones:Opal Can Be Confused with Glass and Some Plastic, and Redish-Brown Chalcedony for its Color.
Treatments:Fracture Filling, Synthetics
Country of Origin:Mexico, Brazil

Mexican Fire Opal Care

Ultrasonic Cleaning:Never
Steam Cleaning:Never
Warm Soapy Water:Safe
Chemical Attack:Avoid
Light Sensitivity:Stable
Heat Sensitivity:May Crack


  • Gem Reference Guide, Los Angeles: Gemological Institute of America, 1988. Pp. 164-167.
  • Newman, Harold. An Illustrated Dictionary of Jewelry, New York: Thames and Hudson, 1981. Pp. 126.
  • Schumann, Walter. Gemstones of the World, New York: Sterling Publishing, Co., 1977. Pp. 152.