On a plain black stone the polish is not a finishing touch — it is most of what you are buying. There is no colour to grade, no clarity to assess and no play of light to judge. What is left is the surface, and the difference between a good polish and a rushed one is visible across a room.

The stone

8.20 carats, which is 9.01 ratti. Rs. 5,700, about Rs. 695 per carat, reference GS-BL-0014. One piece only.

What a good polish looks like

• A mirror, not a sheen. Hold it under a light and look at the reflection. A properly finished agate reflects a sharp, undistorted image of the light source. A rushed one gives a soft, smeared glow.
• No orange peel. Tilt it slowly. Fine ripples across the surface — the trade calls it orange peel — mean the final stage was cut short.
• No scratches at the girdle. The edge is where polishing wheels leave marks, and where a careless finisher stops caring.
• Depth. A well-polished black stone looks like it goes inward. A dull one looks painted on.

Why agate rewards polishing

Agate is cryptocrystalline — made of quartz crystals far too small to see individually — so there are no crystal boundaries to interrupt the surface. That structure takes a glassy finish more readily than almost any other stone of its hardness. Which means a dull black agate is not difficult material; it is a job finished too quickly. At 6.5 to 7 on the Mohs scale there is no technical excuse.

Keeping the polish

Warm soapy water and a soft brush, then dry it. Avoid bleach, drain cleaner and anything abrasive, including toothpaste, which people reach for surprisingly often and which scratches a polished surface. No ultrasonic cleaners. Store it away from harder stones — a sapphire or topaz rattling against it in a box will mark it over time.

If a stone does dull after years of wear, agate can be repolished. It loses a fraction of a carat and comes back sharp.

The colour

Black agate is almost always dyed — standard for the stone type and on our specification sheet rather than hidden. A sugar solution followed by acid carbonises inside the stone's pores and blackens it from within. Worth knowing in this context: the dye goes into the stone, not onto it, so polishing does not remove or thin the colour. Our black agate buying guide explains the process.

Glass gives itself away on the surface too

A glass imitation often shows mould seams near the base and round gas bubbles under a loupe, and it warms in the hand faster than stone does. Our guide to spotting dyed and glass aqeeq runs through the checks.

Ordering

One piece only. Shape and measurements have not been recorded; ask on WhatsApp at +92 308 887 3888 and we will measure it. 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. More in the black agate collection.

This particular stone

This listing is one natural black agate with a weight of 8.2 Carat. Its price is Rs. 5,700 — roughly Rs. 695 for each carat. Treatment: treatment not tested. Quote reference GS-BL-0014 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.

From six carats up a stone becomes the centre of attention. It wants a broader shank or a secure claw setting and suits an occasion ring, a signet or a centre pendant. Clean natural material of this size turns up far less often, and the per-carat rate reflects that.

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.