A cabochon is a stone cut with a smooth domed top and a flat base, with no facets at all. It is the oldest way of shaping a gem — older than faceting by thousands of years — and for an opaque stone like black agate it is still the right answer.

The stone

5.95 carats, which is 6.54 ratti. Cabochon cut. Rs. 4,200, about Rs. 706 per carat, reference GS-BL-0011. One piece only.

Why opaque stones are cut as cabochons

Faceting exists to bounce light around inside a transparent stone and send it back to your eye. That is why a sapphire sparkles. In an opaque stone no light gets inside, so facets have nothing to work with — they would simply chop the surface into dull little planes. A dome does the useful thing instead: it presents one continuous polished surface that catches a clean highlight and lets the eye read the material itself.

There is a second, practical reason. A cabochon has no sharp edges or points, so it is far less likely to chip in a ring — which matters for a stone worn daily.

What to look for in a cabochon

• An even dome. Run your eye along the profile. It should curve smoothly from edge to centre with no flat spot on top, which usually means the cutter was saving weight.
• Enough height. A very shallow cabochon looks lifeless and is fragile at the edges. A good dome has presence.
• A symmetrical outline. Fold it in half in your mind both ways; both halves should mirror.
• A flat, even base. It has to sit properly in the bezel without rocking.
• A clean girdle. Even edge thickness all the way round, with no chips or thin spots.

Cabochon or faceted black agate?

Both exist and we list both. A cabochon is the traditional ring stone — soft, rounded, understated. Faceted black agate reads sharper and more deliberate, closer to art deco onyx jewellery. Neither is better made; they suit different pieces. Compare them in the black agate collection.

The dye

Black agate is almost always dyed — standard for this stone type and stated on our specification sheet rather than hidden. A sugar solution followed by acid carbonises inside the pores and blackens the stone from within. Permanent, stable, natural agate underneath. Our black agate buying guide explains it.

Setting and care

A low full bezel suits a cabochon perfectly — the rim follows the curve and protects the girdle. Agate is 6.5 to 7 on the Mohs scale: warm soapy water and a soft brush, no bleach and no ultrasonic cleaner. Measurements have not been recorded; ask on WhatsApp at +92 308 887 3888 and we will measure it.

Ordering

One piece only. Flat Rs. 500 delivery anywhere in Pakistan, insured and tracked, dispatched in one to two working days. Cash on Delivery, seven days to return it unused.

This particular stone

This listing is one natural black agate with a weight of 5.95 Carat. Its price is Rs. 4,200 — roughly Rs. 706 for each carat. Treatment: treatment not tested. Quote reference GS-BL-0011 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 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.