You do not see 18 carats of sapphire on a hand every day. This natural blue neelam weighs 18.38 carats, and most people's first reaction to a stone this size is how much of it there is for the money.

The reference is AG-000797. Big sapphires tend to cost less per carat than small ones of similar quality, simply because large clean crystals are harder to find. So judge it by colour and clarity, not by weight alone, and ask for daylight photographs.

With a hardness of 9 on the Mohs scale, it can carry a heavy statement ring, a broad pendant or a bespoke piece. We can talk through a custom silver ring setting on WhatsApp. A stone of this mass does need a sturdy mount, with strong claws or a deep bezel.

As with all sapphire, heating is common in the trade, so ask what we know about this one before you commit. If you want independent lab testing, that is your choice.

In Vedic tradition neelam is linked with Saturn, and an astrologer's advice is customary before wearing it.

If it arrives and is not right, you can return it within 7 days of delivery. Browse the rest of the sapphire collection to compare, and see our sapphire guide.

You pay on delivery after checking it. Karachi usually 1–2 working days, other cities 2–4.

This particular stone

This listing is one natural sapphire, known in Urdu as Neelam, with a weight of 18.38 Carat. Its price is Rs. 30,000 — roughly Rs. 1,632 for each carat. Treatment: treatment not tested. Quote reference AG-000797 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.

Above twelve carats you are into collector territory. Pieces this heavy are usually set as pendants or kept loose, and they are prized for the size of rough they came from. If you do set it, choose a bezel or a heavy claw to protect the edges.

On the Mohs scale sapphire rates 9. Few materials will scratch it, so it copes well with everyday ring wear. A soak in warm water with a drop of mild soap and a soft brush keeps it bright; skip the ultrasonic cleaner if inclusions reach the surface.

Whoever you buy sapphire 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 sapphire for those three points before it is listed, 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. No lab report yet; independent testing welcome. As general background (not a statement about this stone): Most sapphire on the market is heated to improve colour and clarity; unheated stones exist and cost more. 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.