The Magic of Opal Play-of-Color

Opal is unique among gemstones because it doesn't just display a single color—it flashes with all the colors of the rainbow. Roman historian Pliny the Elder once described opal as having "the fire of the carbuncle, the brilliant purple of the amethyst, and the sea-green of the emerald, all shining together in incredible union."

Unlike crystalline gemstones like diamonds and sapphires, opal is amorphous silica. It is composed of microscopic spheres of silica arranged in a grid-like pattern, bound together by water. As light enters the stone and hits these spheres, it diffracts (bends) and splits into spectral colors.

A colorful opal The diffraction of light creates the highly sought-after 'play-of-color'.

Types of Precious Opals

1. Black Opal

Black opals are the most valuable and rarest of all opals. Found primarily in Lightning Ridge, Australia, they have a natural dark body tone (black or dark grey) behind the color. This dark background acts as a canvas, allowing the fiery colors to pop with magnificent intensity.

2. White and Crystal Opal

Found mostly in Coober Pedy, Australia, white opals have a milky background, while crystal opals are highly transparent. The play-of-color is beautiful but more subdued than black opals because the light background washes out the intensity slightly.

3. Boulder Opal

Boulder opal forms in the cracks of ironstone boulders in Queensland, Australia. When lapidarists cut boulder opal, they leave a layer of the brown ironstone on the back. The dark ironstone backing functions exactly like black opal, making the colors incredibly vivid, and the natural matrix creates beautiful earthy patterns.

4. Ethiopian Hydrophane Opal

Discovered relatively recently (2008), Welo opals from Ethiopia brought affordable, high-quality opals to the global market. They are primarily hydrophane, meaning they absorb water. This requires very specific care, but they exhibit stunning multi-directional flashes of neon red and green.

What are Doublets and Triplets?

Because pure, solid, high-quality opal is so expensive, the jewelry industry created composites to make it affordable:

  • Solid Opal: 100% natural opal cut from the earth.
  • Doublet: A thin slice of precious crystal opal glued to a backing of dark plastic or ironstone to enhance color.
  • Triplet: A slice of precious opal sandwiched between a dark backing and a clear quartz or glass dome on top.
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Doublets and triplets must never be submerged in water. Over time, water will deteriorate the jeweler's glue, causing the layers to separate and turn cloudy white.

Caring for Your Opal Jewelry

Opals contain between 3% to 21% water. They are soft (5.5 to 6.5 on the Mohs scale) and can scratch easily. More importantly, they are susceptible to sudden temperature changes, which can cause the water to expand or contract, cracking the stone—a sad phenomenon known as crazing.

The Do's of Opal Care:

  1. Clean mildly: Use only a very soft, damp cloth with non-detergent soap.
  2. Wear them properly: Opals are best suited for pendants and earrings. If you wear an opal ring, wear it only on special occasions where you won't bump your hands into hard surfaces.
  3. Store with care: Store them in soft cotton away from intense heat or dry environments (like safe deposit boxes).

The Don'ts of Opal Care:

  1. NO Ultrasonic Cleaners: The harsh vibrations will shatter them.
  2. NO Chemicals: Keep opals away from bleach, perfume, body oils, and hand sanitizers.
  3. NO Sudden Heat: Do not walk out of a freezing snowy environment directly into an intensely hot sauna while wearing an opal ring.

By treating opals with a little bit of respect and care, they will reward you with a lifetime of fiery, dancing colors!