At 65.9 carats this Afghan aquamarine is a collector-sized piece, so here are six points worth checking before you order.

• Stone: natural aquamarine, Beruj in Urdu, from Afghanistan, sea blue in tone.
• Weight: 65.9 carats, much heavier than typical ring stones, so think pendant, display piece or a large custom mount.
• Price: Rs. 28,130, about Rs. 427 per carat, reference GS-000259.
• Hardness: 7.5 to 8 on the Mohs scale.
• Heat: aquamarine is commonly heated to clear greenish tints. Ask us about this stone.
• On arrival: hold it to the light and look for even colour and undamaged edges.

Such a stone is best handled with some respect. Its hardness protects it from scratches, but the sheer weight makes drops dangerous, so open the parcel over a soft surface. More choices are in the aquamarine listings, and inspection before payment is part of Cash on Delivery.

For a stone of this scale, a custom silver mount is worth a conversation on WhatsApp at +92 308 887 3888. Simple, strong settings usually work best, since the colour of aquamarine is its main feature and it needs very little decoration around it.

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 aquamarine guide.

This particular stone

This listing is one natural aquamarine, known in Urdu as Beruj, with a weight of 65.9 Carat. Its price is Rs. 28,130 — roughly Rs. 427 for each carat. Origin: Afghanistan. Treatment: treatment not tested. Quote reference GS-000259 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 aquamarine rates 7.5 to 8. It handles daily wear, but a hard knock can still nick an exposed corner, so a protective setting is a sensible choice. Clean it with warm soapy water and a soft brush, and keep it away from abrasive cleaners and high heat.

Whoever you buy aquamarine 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 aquamarine 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): Aquamarine is commonly heated to remove green tones and leave a purer blue. 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.