Topaz sits at 8 on the Mohs scale, well above quartz and close to the point where a ring stone can take everyday life in its stride. It resists scratches better than amethyst, opal or moonstone. Its one weakness is a flat cleavage plane, which can split the stone if an edge takes a hard blow.

That is worth keeping in mind with this 10.90 carat blue topaz. A stone this size meets knocks easily, so a ring should have protective metal around the girdle, while a pendant sidesteps most of the risk. The blue is the usual result of irradiation and heating, accepted across the trade and stable over time. Message us on WhatsApp quoting AG-BL-0007 and we will tell you what we know about this exact piece.

Its rate per carat is higher than several other blue topaz listings in the shop, so compare it with nearby weights in the blue topaz collection and ask for photos in different light before you decide.

Cleaning and storage

Wash it in lukewarm water with a drop of mild soap and a soft brush, then dry it with a cloth. Avoid ultrasonic cleaners if the stone shows any fracture. Keep it in its own pouch, away from harder gems like sapphire. The topaz care guide covers this in more detail.

Pay only after you have opened the parcel and checked the stone. Karachi usually receives orders in 1 to 2 working days, other cities in 2 to 4, and unused stones can be returned within 7 days.

This particular stone

This listing is one natural blue topaz with a weight of 10.9 Carat. Its price is Rs. 16,350 — roughly Rs. 1,500 for each carat. Treatment: treatment not tested. Quote reference AG-BL-0007 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 blue topaz rates 8. Few materials will scratch it, so it copes well with everyday ring wear. A soak in warm water with a drop of mild soap and a soft brush keeps it bright; skip the ultrasonic cleaner if inclusions reach the surface.

Whoever you buy blue topaz 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 blue topaz for those three points before it is listed, 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. No lab report yet; independent testing welcome. As general background (not a statement about this stone): Blue topaz gets its blue colour from irradiation and heating — this is standard for the stone and the colour is stable. 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.