Onyx Signet Ring (Silver)
- Free worldwide shipping
- Waterproof, heatproof and sweatproof
- Hypoallergenic, won't turn skin green
- In stock, ready to ship
- Backordered, shipping soon
- Estimated delivery: 5 November - 10 November
A men's silver onyx signet ring that won't turn your skin green. It's hypoallergenic 316L stainless steel, waterproof and sweatproof, and it won't rust or fade. Black onyx sits at the centre of a 16mm wide signet, 4mm thick, polished, with a curved edge and a comfort fit band.
The black stone against polished steel works with a shirt and tie or with streetwear. Wear it on your little finger, where signets traditionally go, or on your index finger. Onyx has long been linked with strength and protection.
For a gift, add a gift box in your basket for £3.95. Every piece already comes in a black velvet gift bag.
It comes in US sizes 7 to 13 (UK N½ to Z½). Measure the finger you'll wear it on, and if you're between two sizes, go up one.
- Material: 316L stainless steel, black onyx
- Width: 16mm
- Thickness: 4mm
- Finish: polished
- Edge: curved
- Band fit: comfort
- Sizes: US 7 to 13 (UK N½ to Z½)
- Comes with: black velvet gift bag
✓ Dispatched from the UK
✓ Returns and exchanges within 30 days of arrival
✓ Free worldwide shipping
Ring size guide
Our rings come in US sizes 6 to 13. Some start at 7 or stop at 12, so check the sizes on the product page before you order.

How to measure your finger
- Wrap a strip of paper or string round the base of the finger.
- Mark where the two ends meet.
- Lay it flat against a ruler and match the length in mm to the circumference column.
Already own a ring that fits? Measure across the inside for the diameter.
If you know your UK size, find your letter in the UK column and order the US size next to it.
Between sizes? Go up.
| US | UK | Diameter (mm) | Circumference (mm) |
|---|---|---|---|
| 6 | L½ to M | 16.5 | 52 |
| 7 | N½ to O | 17.3 | 54 |
| 8 | P½ to Q | 18.1 | 57 |
| 9 | R½ to S | 18.9 | 60 |
| 10 | T½ to U | 19.8 | 62 |
| 11 | V½ to W | 20.6 | 65 |
| 12 | X½ to Y | 21.4 | 67 |
| 13 | Z½ to Z+1 | 22.2 | 70 |
Material: 316L stainless steel
The metal
316L is a stainless steel alloy. It's strong, non-magnetic and handles high temperatures, and it resists corrosion and staining. It needs little looking after, so it suits jewellery you wear every day.
Made from
69% iron, 18% chromium, 10% nickel, 2-3% molybdenum and 0.03% carbon. The maker heats the metals to a very high temperature and quenches them, which gives the steel its crystalline structure.
Cleaning
Wash it in hot, soapy water and rinse it well so it doesn't mark. Wipe it with a microfibre cloth to keep it looking new.