Copper oxide, also known as verdigris, is often found on old jewellery, brass or coins. It is usually a greenish or black colour and forms clumps of deposits. Over time, the copper oxide can cause severe damage to the affected pieces. To avoid permanent damage, remove copper oxide stains from the material as soon as possible. Accomplish this using simple household items with an acidic base to eat away the copper oxide deposits.
Cut a lemon in half and dip the fruit side in salt to coat the fruit to give it an abrasive layer similar to sandpaper.
Pour a few tablespoons of salt on the metal surface affected by copper oxide.
Scrub the metal surface with the lemon covered in salt to remove the copper oxide. The acids in the lemon loosen the copper oxide and the abrasiveness of the salt crystals scrape away the loosened particles.
Rinse the metal with warm water and dry immediately to reduce the likelihood of rust. Polish the metal to regain its previous finish.
Fill a small container with white vinegar or lemon juice.
Scrub the jewellery or small object with a toothbrush to remove any loose particles of copper oxide.
Submerge the jewellery or other small object in the vinegar or lemon juice for 20 minutes.
Use the toothpicks or cotton swabs to further remove the copper oxide deposits.
Scrub the piece with the toothbrush and repeat the process until the copper oxide stains are removed.
Many special cleaning agents have been created to remove a variety of stains caused by metal deposits.