The oxidation process on silver jewellery refers to the chemical reaction between silver and oxygen in the air, leading to the formation of silver oxide (Ag2O) on the surface of the jewellery. This reaction is also known as tarnishing.
The image on the left shows a sterling silver bracelet which is heavily tarnished. The same bracelet is shown on the right after it has been cleaned with a specialist jewellery cleaning solution.
When silver jewellery comes into contact with air, it undergoes a slow oxidation process due to the presence of moisture and sulphur-containing compounds in the atmosphere. The oxygen reacts with the surface of the silver, forming a layer of silver oxide. This silver oxide layer appears as a dull, darkened coating on the jewellery, giving it a tarnished or blackened appearance.
The oxidation process can be influenced by several factors, including humidity, exposure to chemicals (such as perfumes, lotions, or cleaning agents), and the pH of the surrounding environment. High humidity and exposure to certain chemicals can accelerate the tarnishing process.
It is important to note that tarnishing does not mean that the silver jewellery is damaged or of poor quality. It is a natural reaction that occurs with exposure to air and can be addressed with proper cleaning and maintenance.
To remove tarnish from silver jewellery, various methods can be used, such as:
Polishing: Gently rubbing the jewellery with a soft cloth or a specialized silver polishing cloth can remove the tarnish and restore its shine.
Silver cleaning solutions: Commercial silver cleaning solutions are available that can effectively remove tarnish. Follow the instructions provided with the product and ensure it is suitable for the type of jewellery you have.
Baking soda paste: A paste made from baking soda and water can be applied to the tarnished areas, gently rubbed, and then rinsed off. This method is useful for removing light tarnish.
Professional cleaning: If the tarnish is severe or difficult to remove, taking the jewellery to a professional jeweller for cleaning and restoration may be the best option.
To prevent or minimize tarnishing, you can take several precautions:
Proper storage: Store silver jewellery in a cool, dry place, preferably in an airtight container or a jewellery box with anti-tarnish properties.
Avoid exposure to chemicals: Remove silver jewellery before applying lotions, perfumes, or household cleaning agents as these can accelerate tarnishing.
Regular cleaning: Clean your silver jewellery periodically to remove any build-up of oils, dirt, or other substances that can contribute to tarnishing.
Protective coatings: Some jewellers offer protective coatings, such as lacquer or rhodium plating, which can act as a barrier against tarnish. However, these coatings can wear off over time and may need reapplication.
By following these steps and maintaining regular care, you can keep your silver jewellery looking its best and minimize the effects of tarnishing.