The honest part first. Tanzanite does not come out of the ground looking the way it does in a jeweller's window; its blue-violet tone is nearly always the result of heating, which dealers accept as routine and permanent. We say so plainly for this 4.25 carat stone so there are no surprises. If you would like us to tell you what we know about this specific piece, write to us, and independent lab testing is always your option.

What we can state: it is a natural tanzanite from Tanzania, 4.25 carats, blue-violet in colour, and on the finer side among the tanzanites we list.

With a hardness of 6 to 7 on the Mohs scale it needs gentle treatment. It is well suited to a pendant, and a ring should have a sheltered setting. Clean it with lukewarm water and a soft cloth, never steam or ultrasonic machines, and store it apart from harder stones.

The reference is AG-000476. See our tanzanite stones for comparison.

Pay the rider only after you have opened the parcel and checked the stone. We deliver across Karachi in 1–2 working days and to other cities in 2–4, and unused stones can be returned within 7 days. Our tanzanite guide is worth a read.

This particular stone

This listing is one natural tanzanite with a weight of 4.25 Carat. Its price is Rs. 20,630 — roughly Rs. 4,854 for each carat. Origin: Tanzania. Treatment: treatment not tested. Quote reference AG-000476 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 tanzanite rates 6 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 tanzanite 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 tanzanite 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): Almost all tanzanite is heated to produce its blue-violet colour; this is standard and 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.