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Home » Gemstones » Opal » Fire Opal


Fire Opal

A translucent to transparent opal with a wonderful fire-like background color of yellow, orange or red.



What is Fire Opal?



"Fire Opal" is a term used for colorful, transparent to translucent opal with a background color that is a fire-like hue of yellow to orange to red. It might or might not exhibit "play-of-color" (the typical flashes of spectral colors that can be seen when a precious opal is turned under a source of light). Most fire opal does not have play-of-color. The defining characteristic of fire opal is the fiery hue of yellow, orange or red that is a uniform background color throughout the stone.

The value of a fire opal is based upon the desirability and uniformity of its color, with yellow being on the low end of value and red being on the high end. Transparent stones are preferred over translucent stones. The best fire opal typically sells for prices that are much lower than the best precious opal; however, fire opal specimens with exceptional color will sell for higher prices than some specimens of precious opal with less impressive play-of-color.


How are Fire Opals Cut?



Fire opals are cut in a variety of ways. Some are cut as faceted stones, others are cut as cabochons. The cutter decides how he/she thinks the stone will be most attractive. Transparent fire opals are usually faceted unless they have obvious play-of-color, in which case the stone will generally be cut into a cabochon to display the play-of-color. Translucent stones are often cut into cabochons, but it is not unusual to see a translucent to nearly opaque fire opal with an attractive color cut into a pretty faceted stone. The three stones in the photo at right are wonderful examples of translucent stones that have been faceted.

Fire opal is a relatively fragile stone. It has a hardness of between 6 and 6.5 on the Mohs Scale, which makes it vulnerable to abrasion. It also chips easily. It is best used in earrings, brooches and pendants that will not be subject to rough wear. It is not durable enough to be an excellent choice for a ring stone. If it is used in a ring, the mounting should be designed to protect the stone and the ring should not be worn when it might be subject to abrasion or impact.


Public Confusion with the Term "Fire Opal"



There is some public confusion with the material known as "fire opal" and the gemstone phenomena known as "fire" and "play-of-color." What do the terms "fire" and "play-of-color" mean?


"Fire"



"Fire" is a name used for flashes of spectral colors that are produced by the dispersion of light into its component colors as it passes through a transparent material. Most people are familiar with how a prism splits white light into a spectrum of its component colors. That phenomenon is known as "dispersion." Diamonds are famous for their colorful sparkle of light known as "fire" which is also caused by dispersion. Fire opal does not exhibit dispersion, thus it does not have "fire" like a diamond.


"Play-of-Color"



"Play-of-Color" is a name used for the flashes of spectral colors that are produced by "precious opal." Those colors are produced when light is scattered by an array of microscopic silica spheres that are stacked to make up the color-producing parts of a precious opal. The technical name of this light scattering is "diffraction." This same type of color is produced when droplets of water in Earth's atmosphere interact with sunlight to produce a rainbow. The rainbow colors of iris agate are also produced by diffraction. Fire opal will occasionally exhibit "play-of-color." When it does, some people call it "precious fire opal."


What is "Fire Opal"?



Fire opal is the name used for a colorful material with a limited range of background colors. It is not a name given because of a phenomenon. It is an opal with an attractive background color that ranges from yellow to orange to red. The attractive background color is what defines the stone.


Fire Opal Localities



Mexico has been the world's primary source of fire opal for decades. The Mexican deposits produce significant amounts of transparent to translucent, bright orange to orange-red material. Some of the transparent material is faceted, mounted in commercial jewelry, and described as "tangerine opal" because of its color. Smaller amounts of fire opal are produced in Australia, Brazil, Ethiopia, Honduras, Guatemala, Nevada and Oregon.




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Fire Opal
These three stones show the color range of "fire opal," a name given to specimens of translucent to transparent common opal with a wonderful fiery background hue that is present throughout the stone. The orange and yellow stones have a sleepy translucence, while the red stone is almost opaque.


Oregon Fire Opal
The orange stone shown here is a faceted fire opal cut from material mined in Oregon. It is 9 x 7 millimeters in size and weights about 1.2 carats.


Red Fire Opal
Red is the most desirable color of fire opal, with transparent specimens being more desirable than translucent. This is an 8 x 10 millimeter oval cut from material mined in Mexico. It weighs about 1.95 carats. Many people call a red fire opal like this one a "cherry opal" because of its color.



Nevada Fire Opal
The stone shown here is a faceted yellow fire opal cut from material mined in Nevada. It is a 9 millimeter round that weighs about 1.7 carats.


Opal photos Opal Photos
Precious opal Precious Opal
Fire opal Fire Opal
Common opal Common Opal
Black opal Black Opal
Boulder opal Boulder Opal
Opal triplet Assembled Stones

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