A natural sunstone of 7.75 carats, about 8.52 ratti, at Rs. 1,760 – roughly Rs. 227 per carat.

This is the liveliest stone in the category, and here is the measurement

Schiller is the whole point of sunstone, and it is the one quality most often claimed without evidence. So we measured it rather than asserting it.

Counting the share of the stone's face made up of bright, warm-toned flecks – points clearly brighter than the surface immediately around them – this stone reads 3.37%. Across the ten sunstones in this category that figure runs from 1.21% to 3.37%, so this is the highest of the ten.

The second measurement matters as much, and it is about where the flecks sit rather than how many there are. Dividing the stone's face into a grid, 87% of its flecks fall inside the busiest quarter of that grid – and on every other stone in this category the figure is 91% or higher. In other words this stone not only has the most glitter, its glitter reaches further across the dome than on any of the others, so it catches light from more angles instead of flashing from one spot.

What copper schiller actually is

Sunstone is a feldspar. As the crystal cooled, microscopic plates of copper came out of solution and settled in parallel sheets inside it. Light entering the dome strikes those sheets and bounces back as a metallic glint that moves when you move the stone. The effect has a name of its own, aventurescence, and it is the reason the stone is called sunstone at all.

It is not a treatment and not an inclusion in the flaw sense. It is the stone's defining feature, and the thing you should turn the stone in the light to check before buying any sunstone from anyone.

Honest about the rest of it

The body colour is a deep brown – about 91% of the face reads as brown and it is among the darker stones here, with an average brightness of about 80 on a 0-255 scale. The glitter stands out because the ground behind it is dark. If you want a lighter, more orange stone, this is not it. The rate is also at the bottom of our range at Rs. 227 per carat, which, for the stone with the strongest schiller, we are content to point out rather than hide.

Softer than household dust

At Mohs 6 to 6.5, sunstone is softer than the quartz in ordinary airborne dust, about 7. A daily-worn ring will slowly lose its polish, which matters more here than usual: a dulled surface scatters light before it can reach the copper inside, so the sparkle fades with the shine. Re-polishing restores both and costs little.

What has not been tested

Sunstone is usually untreated, and that is the honest general position. This stone has no laboratory report and its treatment has not been tested, so that is the trade norm rather than a finding about this piece.

Care and ordering

Warm water, mild soap, a soft cloth. No ultrasonic cleaner, no steam. One stone, sold once. Message us on WhatsApp for more photographs, and we deliver across Pakistan.

This particular stone

This listing is one natural sunstone with a weight of 7.75 Carat. Its price is Rs. 1,760 — roughly Rs. 227 for each carat. Treatment: treatment not tested. Quote reference GS-SS-0006 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 sunstone rates 6 to 6.5. 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 sunstone 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 sunstone 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): Sunstone is usually untreated. 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.