Opal: The Gem of Fire, Rainbows, and Mystery

Opal is unlike any other gemstone—a kaleidoscope of color captured in stone. Revered for its enchanting “play-of-color,” opal has been called “the Queen of Gems”, encompassing the hues of all other stones within its ethereal glow. With a history shrouded in myth, magic, and mystique, opal is a symbol of imagination, transformation, and emotional depth.

A Gemstone of Light and Illusion

The word “opal” is derived from the Sanskrit “upala”, meaning “precious stone,” and later from the Greek “opallios”, meaning “to see a change in color.” This shifting iridescence—known as play-of-color—makes opal one of the most visually captivating gemstones in existence. No two are ever alike.

Unlike crystalline gemstones, opals are amorphous, formed from hydrated silica and often composed of up to 20% water. Their color play results from microscopic silica spheres diffracting light, producing shifting flashes of red, green, blue, and more.

Types of Opal

Opals are incredibly diverse, and their classification depends on body tone, transparency, and the nature of their color play:

• Precious Opal: Displays vivid play-of-color. Includes:

  • White Opal (light body color)

  • Black Opal (dark body color with electric color flashes; most prized)

  • Crystal Opal (transparent or translucent with vivid color)

  • Boulder Opal (forms in ironstone with dramatic contrasts)

• Fire Opal: Typically transparent to translucent with bright orange, red, or yellow hues. May or may not show play-of-color. Found primarily in Mexico.

• Common Opal (or "Potch"): Lacks play-of-color but can be beautifully colored in pinks, blues, greens, and purples.

 

History: A Gem of Myth and Magic

Opals have inspired legends for over 4,000 years. The Romans believed opals contained all the virtues of every other gemstone, calling them symbols of hope and purity. In Arabic folklore, they were said to fall from the sky in flashes of lightning, capturing that fire within. In Europe, opals symbolized luck and prophecy until superstitions in the 19th century briefly tainted their reputation.

Perhaps the most famous historical opal is “The Burning of Troy,” a legendary gem once owned by the Spanish Crown, praised for its blazing inner fire.

WOW FACT!!

The Olympic Australis Opal is the largest and most valuable opal ever found, weighing an extraordinary 17,000 carats (3.45 kg). Discovered in Coober Pedy, South Australia, in 1956, it remains uncut and 99% gem-quality, making it a priceless natural marvel. Australia, which supplies over 90% of the world’s opals, is also home to the famed black opals of Lightning Ridge.

Mohs Scale:

Opals rank 5.5 to 6.5 on the Mohs hardness scale, which makes them softer and more delicate than many other gemstones. They can be prone to scratching, cracking, or crazing (fine surface fractures), especially if exposed to dryness or sudden temperature changes.

Chemical Composition:

Opal is hydrated silica with the formula SiO₂·nH₂O. Its water content ranges from 3% to 20%, depending on type and origin. The gem’s iridescent effect is caused by the diffraction of light through uniform silica spheres arranged in a grid-like pattern within the stone.

How to Buy Opal Jewelry

Color

In opals, both body color and play-of-color matter. The most valuable opals display:

• Bright, multi-hued flashes (red being rarest and most valuable)

• Broad pattern coverage across the surface

• Strong contrast between play-of-color and body tone
  Black opals with vivid color flashes are the most sought-after, while white and crystal opals offer soft, pastel-like brilliance.

Cut

Opals are usually cut into cabochons (smooth domes) to highlight their color play. Thin opal layers are often set on darker backing materials to enhance appearance—these are called doublets or triplets (with added protective tops).

Clarity

High-quality opals should be free from cracks, haziness, or dull areas. Crystal opals should have good transparency without cloudiness. Any sign of crazing or drying indicates instability.

Character

Opal is pure personality in gemstone form—alive with shifting color and mystery. Whether you prefer the intensity of a black opal, the sun-warmth of fire opal, or the gentle romance of white opal, every piece is uniquely expressive.

Caring for Opals

• Clean: Use a soft cloth with lukewarm, soapy water. Avoid soaking.

• Avoid: Ultrasonic cleaners, steamers, extreme heat, and prolonged dryness.

• Store: Wrap individually in moist cotton or padded fabric in a sealed bag. Avoid storing in airtight safes or dry environments, which can dehydrate the stone over time.