Jewels are produced in untreated 925 silver, burnished to enhance every detail of the jewel. It is recommended to use specific products for cleaning silver jewelry. Silver can react chemically in contact with sea water, thermal and sulphurous water or water with a strong presence of chlorine (swimming pool).
In some cases the acid pH of the skin or an excessively damp environment can cause chemical reactions that lead the jewel to blacken. This is the natural course of the material, I don’t treat metal surfaces with any chemical process due to its stylistic choice.
The Bronze fears humidity and reacts differently depending on the degree of acidity of the wearer’s skin; it can darken and leave a greenish halo on the skin. This is absolutely normal and is not harmful to the wearer. A thin veil of transparent enamel inside rings and bracelets can solve the problem of greenery.
In case of oxidation, it is possible to polish the objects with a cloth treated with those commonly used for silverware. For cleaning, simply rub them with vinegar mixed with water and ammonia (one third of each), rinsing thoroughly with warm water and drying well with a soft cloth.