Start with the honest part. Tanzanite does not come out of the ground with the colour you see in a jeweller's window: the blue-violet tone is nearly always the result of a firing step that dealers accept as routine and lasting. 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, or have it checked independently, write to us or ask for lab testing.

What we can state about the stone: it is a natural tanzanite from Tanzania, weighs 4.25 carats and shows a blue-violet colour. It is priced at Rs. 20,630, about Rs. 4,854 per carat, on the higher side among our tanzanites.

Because the hardness is 6 to 7 on the Mohs scale, treat it gently. It is well suited to a pendant, and a ring should have a sheltered setting. Clean it with lukewarm water and a soft cloth, not with steam or ultrasonic machines, and store it separately from harder stones.

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

Pay Cash on Delivery once you have opened the parcel and seen the stone yourself, anywhere in Pakistan, with 7 days to return it if you change your mind. Before you choose, read our tanzanite guide.

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 GS-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, 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): 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.