Yes, it is common for a solid copper bracelet to leave a greenish or grey-green mark on the skin. This happens because copper reacts with perspiration and the skin's natural acids, forming a harmless trace on the surface. It is not a defect and does not mean the bracelet is of poor quality.
The mark is more likely to appear in warm weather, during physical activity, or when the bracelet gets wet – all conditions that increase moisture and salt on the skin. The discolouration is temporary and washes off with soap and water. It does not stain permanently.
If you prefer to minimise these marks, you can:
- Remove the bracelet before heavy exercise, swimming, or showering.
- Wipe the bracelet dry with a soft cloth after wearing it, especially if you sweat.
- Wear it on a wrist that stays relatively dry, and avoid wearing it too tightly.
Keep in mind that the green mark is harmless and is simply a reaction between copper and your skin's chemistry. Some people see it more often than others – it depends on your individual skin acidity and how much you sweat.