Peacock Opal Identification Guide
Identifying peacock opal by its multicolor play-of-color, low density, and how to separate genuine precious opal from glass and resin imitations.
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What Peacock Opal Looks Like
Peacock opal is a trade name for precious opal showing a vivid multicolor play-of-color dominated by blues, greens, and teals reminiscent of a peacock's plumage. It is hydrated silica (SiO2·nH2O) and can be on a light, dark, or translucent base. The body may be milky, gray, or blue, with bright rolling flashes of color that move as the stone is tilted. Luster is vitreous to waxy.
Quick visual cues
- Shifting rainbow flashes weighted toward blue-green
- Flashes move and change as you rotate the stone (true play-of-color)
- Waxy-to-glassy luster, translucent to semi-opaque body
- Light weight in the hand
Step-by-Step Field ID Checklist
- Tilt under a point light source and watch the color patches flash and migrate — genuine play-of-color shifts with angle.
- Examine the pattern with a loupe: natural opal shows irregular, three-dimensional color patches; imitations often show a flat "chicken-wire" or columnar pattern.
- Test hardness: opal is 5.5-6.5 Mohs.
- Check fracture: conchoidal, no cleavage.
- Heft it: opal is light, SG ~1.9-2.2.
- Look for layering — doublets/triplets show a flat glue line at the side.
Key Diagnostic Tests
- Mohs hardness: 5.5-6.5.
- Streak: white.
- Cleavage/Fracture: none / conchoidal.
- Specific gravity: ~1.9-2.2 (lighter than glass at ~2.5).
- Magnification: natural opal lacks gas bubbles; man-made opal often shows a regular columnar or lizard-skin pattern.
- Acid: no reaction.
Common Look-Alikes and How to Tell Them Apart
- Synthetic opal (Gilson): shows an unnaturally regular columnar/snakeskin color pattern and often a slightly porous, fizzy appearance under magnification.
- Opal triplets/doublets: a thin opal layer glued to a dark backing; check the side profile for a flat seam and contrived flatness.
- Slocum stone / opalite glass: contains bubbles, is denser (~2.5), and the "fire" is foil-like flakes rather than true play-of-color.
- Labradorite (spectrolite): shows directional sheen (labradorescence) in flat flashes, is harder (6-6.5), denser, and has feldspar cleavage.
- Ammolite: iridescent but is a thin shell over matrix, far thinner color layer.
The decisive proof is true three-dimensional play-of-color + low density (~2.0) + hardness under 6.5 + no bubbles.
Where Peacock Opal Is Found
Much "peacock" precious opal originates from Ethiopia (Welo) and Australia (Lightning Ridge, Coober Pedy), with additional material from Mexico and Brazil. Opal forms by low-temperature deposition of silica gel in volcanic and sedimentary host rocks.
Frequently asked questions
How can you tell if peacock opal is real?
Real peacock opal shows three-dimensional play-of-color that moves and changes with angle, is light (SG ~2.0), hardness 5.5-6.5, has no bubbles, and shows no regular columnar pattern under a loupe.
What does peacock opal look like?
It is a translucent opal with bright shifting rainbow flashes dominated by blues, greens, and teals, like a peacock's tail, over a light or grayish base.
Peacock opal vs synthetic opal — how do I tell them apart?
Synthetic (Gilson) opal shows an unnaturally regular columnar or snakeskin color pattern under magnification, while natural opal shows irregular, three-dimensional color patches.
Is peacock opal the same as labradorite?
No. Labradorite shows directional flat sheen (labradorescence) and is a harder, denser feldspar with cleavage, while peacock opal is hydrated silica with true rolling play-of-color.