Heating is so common in sapphire that experienced buyers treat it as the first question rather than the last. For a stone like this 13.25 carat neelam, the sensible approach is to ask what is known about its treatment, and to request independent lab testing if the answer matters to the price you are paying. We can tell you what we know when you write to us on WhatsApp, quoting GS-000875.

What we know about this stone

It is a natural blue sapphire, neelam in Urdu, with Afghanistan given as the origin. The weight is 13.25 carats and the price is Rs. 24,000, about Rs. 1,811 per carat, a low rate that reflects the size and, as in all sapphire, the colour and clarity on view.

Mohs hardness is 9. At this size a big ring is possible, though many buyers choose a pendant, since heavier stones are happier hanging than banging against surfaces.

Photographs in daylight are the best way to judge such a stone before it arrives. The sapphire collection offers smaller and larger stones for comparison.

Cash on Delivery is available across Pakistan, so you inspect the stone before paying, and returns are accepted within 7 days of delivery. Before you choose, read our sapphire guide.

This particular stone

This listing is one natural sapphire, known in Urdu as Neelam, with a weight of 13.25 Carat. Its price is Rs. 24,000 — roughly Rs. 1,811 for each carat. Origin: Afghanistan. Treatment: treatment not tested. Quote reference GS-000875 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, 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): 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.