Fire Opal

saf-ahyuh r
October Birthstone

Unique and mysterious, fire opals are appropriately named for their fiery cherries, sunburst yellows and deep tangerines. Unlike many other opals, fire opal may not display play of color, and specimens that do are highly valuable. Mexico is one of today's primary fire opal sources, where this fiery gem has been treasured since the time of the Aztecs, who called it "gem of the bird of paradise" in their native language.

Fire Opal Polished
Fire Opal Classification
Common Name Fire Opal
Species Opal
Fire Opal Optical Properties
Transparency Transparent - Opaque
Refractive Index 1.370-1.460 Tolerance: (+0.020/-0.080) Typical 1.42-1.43
Optic Character NA
Polariscope Reaction Singly Refractive (SR) With ADR
Fluorescence SWUV: Inert to moderate greenish brown
LWUV: Inert to moderate greenish brown
Pleochroism None
Fire Opal Characteristic Physical Properties
Hardness 5-6.5
Streak White
Specific Gravity 1.920-2.38 Typical:2.150
Toughness Varies
Inclusions Fire opal might have a cloudy appearance, show color zoning and have mineral, fluid and flake like inclusions. Occasionally pyrite and dendrtic inclusions.
Luster Vitreous, Resinous
Fracture Conchoidal, Uneven
Cleavage None
Fire Opal Chemistry & Crystallography
Chemical Name hydrated silicon dioxide
Chemical Formula SiO2.nH2O
Crystal System NA
Chemistry Classification Silicate

Fire Opal Colors

  • Orange Fire Opal Orange
  • Yellow Fire Opal Yellow
  • Red Fire Opal Red

Fire Opal Spectra

Fire Opal Spectra

Color due to internal structure. Like most fire opals there is very little transmission in the violet blue side of the visible spectrum. In the lighter colored stones as here, absorption sets in about 540nm. but in the darker specimens only red and orange may be transmitted.

Jewelry Television acknowledges the significant scientific contributions of John S Harris, FGA to the study of gemstone spectra and with deep appreciation to him, acknowledges the use of his images and related notes about gemstones and their spectra in the educational materials on this website.

Alternate Names

Precious Opal, Mexican Fire Opal, Brazilian Fire Opal, Cherry Opal, Gold Opal, Sun Opal

Countries of Origin

Tanzania, United Republic Of; Ecuador; Argentina; United States of America (the); Hungary; Madagascar; Kazakhstan; Bolivia (Plurinational State of); Canada; Austria; Turkey; Unknown; Russian Federation (the); Brazil; Honduras; Mexico; Slovakia; Australia; Ethiopia; Indonesia; United Kingdom of Great Britain and Northern Ireland (the)


Avoid water, heat and solvents. Fire Opal is moderately soft, so be mindful of scratching.

Shop Fire Opal

Related Videos

Sisk Gemology Reference

Showcasing 200 gemstones in over 1,000 pages and accompanied by more than 2,000 photos, The Sisk Gemology Reference is a must-have in every collector’s library. Each comprehensive, three-volume set features state-of-the-art photography, detailed illustrations, and scientifically precise descriptions to create an entrancing experience for gemstone amateurs and afficionados alike.

Shop Now


Creation Method

Synthetic Fire Opal

Synthetic Fire Opal was manufactured by Rhea Industries and marketed as “Mexifire®”. The material was first reported in the scientific literature in 2008 and has been modified throughout the years to improve the product currently in the marketplace.

Synthetic Fire Opal Fire Opal
Synthetic Fire Opal Classification
Common Name Synthetic Fire Opal
Synthetic Fire Opal Characteristic Physical properties
Specific Gravity 1.63
Toughness Fair
Inclusions Pinpoint inclusions and zoned turbidity
Tim Matthews


Tim Matthews

Tim Matthews is President and Chief Executive Officer of Jewelry Television® (JTV), as well as a member of the company's Board of Directors. He oversees and leads all aspects of the company's powerful omni-digital retail platform that uniquely specializes in fine jewelry and gemstones. His passion for business and gemstones has led him to become a recognized expert in the field of gemology. He is a life member of the Gemmological Association of Great Britain (Gem-A) and has earned Gem-A's highest degrees, the Gemmology (FGA) and Diamond (DGA) diplomas. He is also a Graduate Gemologist (GG) of the Gemological Institute of America (GIA) and has also completed GIA's Graduate Diplomas in Diamonds, Colored Stones and Pearls. Under his leadership, JTV has become the leader in the sourcing and selling of color gemstones and jewelry.

This page was created on June 27, 2014.

This page was last edited on October 24, 2019.