Is Your Opal Real? What to Check Before Buying in Pakistan

Opal is one of the easiest stones to imitate and one of the hardest to judge from a photo. Its whole appeal is that flash of colour moving across the surface, and glass, plastic and lab-grown opal can all produce a flash of some sort. In Pakistani markets the problem is seldom an outright lie. Far more often a doublet gets called "opal", a synthetic gets called "Australian", or a dyed Ethiopian stone is sold as natural black opal.

This is asli opal ki pehchan step by step: what each imitation is, which checks you can do at home with a torch and a loupe, which questions only a lab can answer, and how to buy so that a mistake costs you nothing.

What genuine opal is

Precious opal is hydrated silica: tiny silica spheres stacked in orderly rows, with water held between them. Light passing through those rows splits into spectral colours, and the colour changes as you tilt the stone. That is what the trade calls play-of-colour. Common opal has the same chemistry but no orderly spheres, so it has a milky body and no moving colour.

Most of the opal sold in Pakistan comes from two places. Australian opal, often from sedimentary deposits, includes the famous black and boulder opals. Ethiopian opal, mostly from volcanic deposits in Wollo, is usually white or crystal with bright colour and is often hydrophane, meaning it soaks up water. Opal is also October's birthstone (see our October birthstone page), and our guides to Australian opal and Ethiopian opal checks go further into each.

The imitations you are most likely to meet

Opalite and other glass

Opalite is a man-made glass that glows bluish against a dark background and orange against a light one. It is sold openly as a crystal-healing stone and sometimes, less honestly, as "moon opal" or just opal. It never shows true play-of-colour; the glow is a soft, even sheen with no separate patches of spectral colour. Look closely and you may also spot round gas bubbles.

Plastic and resin

Some imitations set foil or iridescent flakes in resin. They are very light, feel warm straight away, and the colour sits in flat, glittery fragments instead of patches that roll across the stone as it turns.

Synthetic (lab-grown) opal

Lab-grown opal, often called Gilson or Kyocera opal after the makers who developed it, is built from real silica spheres and can show strong play-of-colour. The giveaway is the pattern. Under a loupe, synthetic opal often has a regular, columnar structure from the side and a "snakeskin" or "chicken-wire" mosaic from the top, as though the colour sits in neat scales. Natural opal patterns are irregular: broad flashes, pinfire dots, rolling bands. Synthetic opal can also be impregnated with resin, which lowers its density.

Doublets and triplets

A doublet is a thin slice of real opal glued to a dark backing, often black glass, ironstone or plastic, to make the colour look stronger. A triplet adds a clear dome of quartz or glass on top to protect that thin slice. Both contain natural opal and are perfectly legitimate when sold as what they are. They are worth far less than a solid stone, and must never be soaked, because water gets into the glue line.

Dyed and smoked opal

Ethiopian hydrophane opal absorbs liquid easily, which makes it simple to darken. Smoking and dyeing turn a white stone dark so it looks like valuable black opal. Sugar-acid treatment does the same thing to porous matrix opal by depositing carbon in the pores. These stones are natural opal, but the dark body is not, and that has to be disclosed.

Home checks that genuinely help

None of these replaces a lab, but together they catch most imitations before you pay.

1. Look at it side-on. Hold it at eye level with a torch behind you. A straight, flat line where two layers meet means a doublet or triplet. A clear dome over a thin coloured layer means a triplet. Solid opal shows the same material top to bottom, even if the colour fades towards the base.
2. Turn it slowly under one light. True play-of-colour appears in distinct patches that switch on and off and change colour with the angle. Opalite glows evenly. Foil imitations glitter in the same spot from every angle.
3. Put a 10x loupe on the pattern. Natural patterns are random. A regular scaly or honeycomb mosaic over the whole face points to synthetic.
4. Check the back. Many doublets have a black, perfectly flat, glossy back. Natural black opal is dark all the way through, and boulder opal shows brown ironstone that looks like rock, not paint.
5. Feel its temperature and weight. Plastic warms almost instantly and feels too light. This won't separate glass from opal, but it rules out resin.
6. Look for bubbles. Perfectly round gas bubbles in the body suggest glass.

Checks to stay away from

Some popular "tests" either damage opal or prove nothing.

• Soaking in water. Ethiopian hydrophane opal goes clear or loses its colour while wet. It usually recovers as it dries, but dyed stones may bleed and doublets may come apart. Never soak a stone you haven't bought.
• The hot needle or flame. Opal holds water inside, and heat can crack it. Never heat it.
• Scratching. Opal is only 5.5 to 6.5 on Mohs, so a scratch test proves nothing except that you have damaged it.
• "Real opal glows under UV." Some natural opal fluoresces and some doesn't, and plenty of imitations do. UV alone tells you very little.

What only a lab can confirm

A home check can show that a stone is assembled or plainly glass. It can't reliably tell you three things:

• Whether a solid stone with good play-of-colour is natural or synthetic, when the pattern isn't textbook.
• Whether a dark Ethiopian opal has been smoked or dyed.
• Whether a stone has been impregnated with resin or polymer to stabilise it.

A gem lab answers these using magnification, specific gravity, infrared spectroscopy and other instruments, and for a higher-value opal it is worth the fee. If you want a lab report on one of our stones, tell us before you order. See our lab-certified opal page and the guide on how to read a lab certificate, so words like "assembled" or "impregnated" on a report make sense.

Treatments that are fine when disclosed

Not every treated opal is a fake. A stabilised opal, a doublet sold as a doublet, or a smoked Ethiopian opal sold as smoked are all honest products at a fair price for what they are. The trouble only starts when the treatment is hidden and the price is that of a solid, untreated stone. Ask the seller to write one of these on the invoice: solid natural opal, natural opal doublet, natural opal triplet, or synthetic opal, plus any known treatment.

Doubts about an opal you already own

Many families have an old opal ring bought on a trip or from a travelling seller. Before assuming the worst, start with the side view. Don't take it out of the setting; just look along the edge with a torch. A visible glue line, or a dark layer under a thin coloured one, means it is assembled, which is still a genuine opal product. If it looks solid and the pattern is irregular, the odds favour natural opal. If the pattern is a neat mosaic, or it is a very large, very bright black opal that cost very little, only a lab report will settle it. Don't have it removed, soaked or polished until you know what it is, because a doublet can lift and a hydrophane stone can stain.

Opal names you'll hear in shops

Sellers use loose names, and a few need care. "Fire opal" can mean genuine orange Mexican opal, or just any opal with strong colour. "Australian opal" sometimes gets used for any good-looking opal, wherever it came from. "Moon opal", "sea opal" and "galaxy opal" are usually trade names for glass or synthetics. If you don't recognise a name, ask what mineral it is. Our Urdu and English gem names list helps with the common ones.

When the price is the warning

A large, bright, solid black opal at a low price should stop you in your tracks. Fine black opal is among the most expensive coloured stones per carat. Ethiopian white opal is far more affordable, which is why it is so common here. That is no reason to doubt it, only a reason to make sure it is described accurately. Our opal price guide explains how type and pattern affect cost.

Buying opal safely

• Ask for side and back photos, not just the face. Assembled stones are easiest to spot from the side.
• Ask for a short video under a single light. Play-of-colour has to move before you can judge it.
• Get the description in writing: solid or assembled, natural or synthetic, origin if known, treatment if any.
• Make sure the weight is for the loose stone, not including a backing or setting.
• Buy where you can inspect before paying.

We photograph every opal on its own and describe it as we find it. Orders go out from Karachi with Cash on Delivery, usually reaching Karachi addresses in 1 to 2 working days and the rest of Pakistan within a few more. Open the parcel, check the stone, and pay the rider only if you are happy, with 7 days to return it afterwards. Browse our opal collection; the 1.50 carat Ethiopian opal and the 1.90 carat Ethiopian opal, for instance, both show their play-of-colour in the listing photos. Our article on wearing opal and caring for it covers what to do once you own one, and the wider real or fake gemstones guide applies the same thinking to other stones.

Shop the stones: opal.