Five carats is a large opal. That sounds odd next to sapphire or agate, where five carats is modest, but opal is cut as a cabochon with a domed top, so it covers far more of the finger than a faceted stone of the same weight. Most of our Australian opals are between two and three carats; this one is at the top of the range.

The stone

5 carats, which is 5.49 ratti. Shape: oval cabochon. Origin: Australia. Rs. 8,850, about Rs. 1,770 per carat, reference GS-000716.

Why a larger opal is not simply dearer

With most gems the per-carat rate climbs steeply with size. With opal it often falls, and this stone shows it: at about Rs. 1,770 per carat it is well below our two-carat stones, several of which pass Rs. 8,000. The reason is that opal is priced on brightness, not weight. A small, vividly flashing stone outprices a large quiet one every time. So a large opal at a modest rate means exactly what it says — size without fireworks — and whether that is the right trade depends on what you want the stone to do.

What a five carat cabochon suits

• A men's silver ring. The traditional broad-shank style carries a cabochon of this size well.
• A pendant. Easier on a soft stone than a ring, because a pendant takes far fewer knocks.
• A statement piece for occasional wear. Sensible with opal, which rewards being worn thoughtfully rather than constantly.

How do I judge the colour?

Hold it at arm's length in daylight and tilt it slowly. Good opal keeps producing colour across a wide range of angles; weaker material flashes once and goes quiet. Ask us on WhatsApp at +92 308 887 3888 for a video under moving light — with opal a video tells you far more than any photograph can, and we are happy to send one before you order.

Solid, not a doublet

We sell solid natural opal. Check any opal edge-on for the straight glue line that gives away a doublet or triplet. Our real versus fake opal guide covers it.

Treatment

Solid opal is usually untreated, though some is smoke- or sugar-treated to darken the background. We have not tested this stone, so the specification says so rather than claiming it is untreated. Independent laboratory testing can be arranged and a certificate of authenticity comes on request.

Care — this matters more than with other gems

Opal is 5.5 to 6.5 on the Mohs scale and holds water in its structure. Soft damp cloth only. Never an ultrasonic or steam cleaner. Keep it away from prolonged direct sun, hot cars and very dry air, all of which can cause the fine surface cracks called crazing. Ask for a bezel setting rather than claws.

Ordering

One piece only. Flat Rs. 500 delivery anywhere in Pakistan, insured and tracked, dispatched in one to two working days. Cash on Delivery, seven days to return it unused. Measurements have not been recorded; we will measure it on request. Compare the range in the Australian opal collection and see how rates are built in our opal price guide.

This particular stone

This listing is one natural australian opal with a weight of 5 Carat. Its price is Rs. 25,000 — roughly Rs. 5,000 for each carat. Origin: Australia. Treatment: treatment not tested. Quote reference GS-000716 when you message us about it. The photographs show this exact stone, so what arrives at your door is the piece you chose on screen.

Between two and six carats is the range most people choose for a gents' ring or a noticeable pendant. Here colour drives the price more than size does, which is why two stones of near-identical weight can be priced very differently.

Whoever you buy australian opal from, make sure of three things: the stone is natural rather than lab-grown, glass or glass-filled; any treatment is stated in writing; and the weight quoted is the weight of the finished stone. We check every australian opal for those three points before it is listed, a certificate is available on request, and because you pay on delivery you can look at the stone — or have it tested — before any money changes hands.

We sell natural stones only and inspect each one before it is listed. Treatment for this stone: Treatment not tested. Certificate available on request. As general background (not a statement about this stone): Solid opal is usually untreated; some opal is smoke- or sugar-treated, and doublets/triplets exist — we sell solid natural opal. Ask us on WhatsApp and we will tell you what we know about this exact stone; independent lab testing is available on request.

A certificate of authenticity is available on request for this stone, and independent laboratory testing can be arranged. Because you pay on delivery, you can also take the stone to a lab of your choice within the 7-day return window. Read more on our authenticity page.