The lush world of opals is multifaceted and wildly diverse, but shining the brightest out of the tangle is the fire opal.
If you’ve never held one in your hands, you might catch an inkling of its feel by gazing into a blistering fire. But wait, there’s a catch. Notice the colors that make for the spectacle. The flaming orange, or darkish red that burn so fierce you can’t really put your finger on what it all means. Literally and figuratively.
Now try to separate the colors and judge them independently. Steady them down. This is what the fire opal does. It tames the fire.
The Colors of the Fire Opal
It’s actually a common enough mistake to think that a fire opal is alight with a heavy red color displayed in all its hues and burning tinges. The name is, granted, a little misleading. So let’s restore some clarity into the matter.
Fire opal is not known for its play of color, but rather for its vivid and consistent body color. An array of red, yellow, orange or brownish is spread uniformly over the stone. They actually give the impression of layered butter. Also, they’re thought to be the natural effect of small amounts of iron present in the opal
The “Fire” That Does Not Burn in the Fire Opal
“Fire” is a title employed in the gem world to define the process of dispersion of light. White light splits into flashes of spectral colors as it passes through the transparent material. Other precious rocks that display a dazzling “fire” show are diamonds.
But not fire opal. The stone does not exhibit the dispersion characteristic, so it can’t have the proper fire of a diamond.
The fire opal 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.
These colors are born when a myriad of microscopic silica spheres make up the color-producing parts of a precious opal. The term might sound familiar to you. It’s called diffraction.
To give you an example occurring in the natural world on a daily basis. These same colors are produced when droplets of water in Earth’s atmosphere interact with sunlight and make… a rainbow.
Fire opal will occasionally exhibit “play-of-color.” When it does, some people call it “precious fire opal.”
Different Fire Opals, Separate Price Tags
The value of a fire opal is tied to the desirability and uniformity of its hues. One important differentiator is the presence of transparency and translucency.
The most sought-after specimens are of the transparent kind, with a play of fire-red orange color. Items carrying such gems can demand a retail price of up to $300 per carat. In contrast, translucent stones don’t pay that well. Brownish or yellowish, they sell at best for $5 a carat.
Also, the best fire opal typically sells for prices that are much lower than the best precious opal.
All in all, one could say fire opal is highly versatile, both in terms of natural design and the accompanying price tags.
Fire Opals in Jewelry
What about flexibility in the hands of jewelers? Considering its high fragility, high water content and penchant for unexpected fissures, the fire opal is a tricky stone to handle.
First, it is the oval which is regarded as the classical shape to mold fire opals in. Not so much the case with Brazilian raw stones, however. Their sheer size means the designs are not confined to one. More liberty in creativity means you can even buy an orange opal skull carved out of the host matrix.
These gems can really be cut in a variety of ways. Some as faceted stones, others as cabochons. There is no rule for cutting a fire opal, only unnerving pressure.
They’re not stubborn stones- their hardness is relatively low, but they don’t make it easier for the cutter. The cutter will decide the step to take, a decision that will yet again come to the gem’s transparency or translucency properties.
The majority of transparent fire opals is faceted. That way, light can cross through and demand the most from the internal structure of the stone. Mounted in commercial jewelry, this type of cut is described as “tangerine opal” because of its color. However, if the play-of-color is well worth it, the gem might instead be cut into a cabochon and yield its flashiest shine.
On the other hand, translucent stones often go cabochon, but can be facetted if it’s one the best varieties.
Still, in the majority of cases, fire opals end up faceted, which adds to their pre-existent fragility. Apart from having to pay attention not to dispel the stone’s play of color, the cutter must also make sure that the gem does not come into close contact with great heat.
How Strong or Weak Is a Fire Opal?
Like other opal gemstones, the fire opal weighs up to ten percent- sometimes even 21 percent in water.
Since the high water content is unevenly distributed, the gem is rather delicate and can crack or become cloudy if exposed to long sessions of strong light. It’s a trait that runs through all opals. Wearers must be aware that their prized possession can crack with time if not properly taken care of.
Experienced jewelers can judge a fire opal’s durability by its origin. The drier the place, the more durable the stone.
Fire opal rates a Mohs hardness of 5.5-6. If unprotected or unshielded by design, it is soft enough to end up scratched when in contact with other sharp, obtrusive objects.
Also, the gem displays low tenacity, which again, in jewelry jargon means it can easily be chipped. All in all, fire opal is best used in such pieces as earrings and pendants.
Where is Fire Opal Found?
Smaller amounts of fire opal can be found in Australia, Ethiopia, Guatemala, Nevada, and Honduras.
However, it is in the open-cast mines of Queretaro, Mexico that the most significant fire opal deposits in the world lie. Germany has been importing them in loads for many decades now.
The Mexican highlands are rigged with a chain of extinct volcanoes. It is in that very same strata that opals flourish, hidden from sight, in the crevices and cavities of earth.
The industrial extraction gives rise to impressive canyons where there were high mountains before, labyrinthine passages where there was solid ground.
Not all Mexican opal is fire opal. Some of it is known as Mexican water opal for its blue or golden hues.
The Past, the Present, the Legend In-between
Fire opals were regarded as love symbols in ancient India and the old Persian kingdom.
The Amerindians believed that a gem containing the fires of the world within could have only been the product of its opposing principle, the waters of paradise.
The Mayas and Aztecs handed down knowledge of the fire opal from generation to generation. They used the gemstone for ritualistic purposes. They called it the ‘stone of the bird of paradise’, and ornamented mosaics with its fiery colors.
Australian Aboriginals legends also mention the gem. It’s said that when the Creator came down from the heavens on a rainbow to bless mankind with a message of peace, the stones he stepped on were inspired with life and sparkle. This, they say, was the birth of opal.