At 3.75 carats, this is a large opal by any measure, and the biggest in this group. Most opals offered in small jewellery sizes sit between one and two carats, so a stone of this weight will be seen from across a room and will give a pendant real presence.

With size comes cost. The price is Rs. 28,500, about Rs. 7,600 per carat, which is higher per carat than our smaller opals. That is usual in gemstones generally: larger pieces are harder to find and are priced accordingly, even where the quality is similar. The reference is GS-000602.

What to look for in large opal

A bigger surface shows more colour play, but it also gives cracks more room to appear. Check for hairlines, cloudy patches and any line along the edge that could mean a doublet or triplet. With a Mohs hardness of 5.5 to 6.5 and more surface to knock, it suits a pendant or a protected ring bezel better than an exposed setting.

This is a natural fire opal with visible play-of-colour. Whole opal is usually left natural; darkened stones exist in the trade. We sell solid natural opal and will tell you what we know about this one if you message us. Independent lab testing can be arranged on request. See smaller stones in the opal collection.

Pay Cash on Delivery once you have opened the parcel and seen the stone yourself, anywhere in Pakistan, with 7 days to return it if you change your mind. Before you choose, read our opal guide.

This particular stone

This listing is one natural opal with a weight of 3.75 Carat. Its price is Rs. 28,500 — roughly Rs. 7,600 for each carat. Treatment: treatment not tested. Quote reference GS-000602 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.

On the Mohs scale opal rates 5.5 to 6.5. That is middle-of-the-road hardness: comfortable in pendants and earrings, and in rings worn with some care. Store it apart from harder stones so it does not pick up scratches, and wipe it with a damp cloth rather than scrubbing.

Whoever you buy 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 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.