Your copper ring is turning your finger green due to a chemical reaction between the copper in the ring, the moisture and acidity of your skin, and the air. This reaction produces a green substance called verdigris.
Understanding Verdigris
Verdigris is essentially copper acetate, a naturally occurring compound that forms when copper corrodes. Here's a breakdown:
- Copper Composition: The amount of copper in the ring significantly impacts the likelihood of your finger turning green. Rings advertised as "copper" may contain alloys with other metals that reduce this effect.
- Skin Acidity: Everyone's skin has a different pH level (acidity). People with more acidic skin are more prone to the green discoloration because the acid accelerates the corrosion of the copper.
- Moisture: Sweat and even just moisture from the air act as catalysts for the chemical reaction.
- The Reaction: The copper reacts with the sweat and oils on your skin (which contain acids) to form copper salts, including copper carbonate and copper acetate (verdigris).
Is it Harmful?
While the green stain can be unsightly, it is generally harmless. Some people might experience mild skin irritation (contact dermatitis), but this is rare.
How to Prevent a Green Finger
Here are some ways to prevent your copper ring from turning your finger green:
- Apply a Barrier:
- Apply a thin coat of clear nail polish to the inside of the ring. You will need to reapply this periodically as it wears off.
- Apply a sealant like jeweler's lacquer.
- Keep the Ring Clean:
- Regularly clean your ring with a jewelry cleaner specifically designed for copper.
- Wipe the ring dry after washing your hands or sweating.
- Consider a Plating:
- Have the inside of the ring plated with a non-reactive metal like rhodium or gold. This is a more permanent solution.
- Hydrate:
- Hydration can impact your skin's pH balance. Drinking enough water can lessen skin acidity in some people.
- Choose Alloys Carefully:
- Choose rings with a lower copper content or copper alloys that are less reactive.
