At 18.45 carats, this black agate is a large stone by any measure, and large in agate terms means a piece that works best on a gents' ring or as a bold pendant. It is a size you wear on purpose. On a slim hand it makes a statement, and on a broad one it looks balanced, so think about the wearer before you decide.

What to look for in agate at this size

With more surface comes more chance of flaws, so check the whole face for evenly applied colour, a smooth polish and a clean edge. Black agate is dyed as standard, so an even black is expected. Hardness is 6.5 to 7, which is fine for a ring with a good bezel.

The cost is Rs. 3,750, about Rs. 203 per carat, the highest rate in this group but still modest for a gem of this weight. Our reference is GS-BL-0024. Compare it with others in the black agate collection.

If you are not sure it will suit you, send us a message on WhatsApp and describe your hand and your usual jewellery; we will tell you honestly what we think.

Order with Cash on Delivery anywhere in Pakistan: open the parcel, check the stone, then pay. If it is not right for you, you have 7 days to return it. Before you choose, read our black agate guide.

This particular stone

This listing is one natural black agate with a weight of 18.45 Carat. Its price is Rs. 3,750 — roughly Rs. 203 for each carat. Treatment: treatment not tested. Quote reference GS-BL-0024 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 black agate rates 6.5 to 7. 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 black agate 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 black agate 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): Black agate is almost always dyed — it is standard for the stone. 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.