Oxidised sterling silver has a lovely matte black surface with a gun metal lustre.
The process of oxidising silver turns the metal's surface black.
I use liver of sulphur to oxidise the sterling silver.
This treatment is called a patina which is just a surface treatment and does not change the internal characteristics of the metal. As any surface treatment it will wear off over time and use, to show the metal underneath.
With wear, oxidisation rubs back, exposing the true metal colour beneath. This will happen at varying speeds depending on how regularly the piece is worn and how much it rubs against clothes and skin.
Rings and bangles tend to wear the fastest, pendants a little slower, and earrings the slowest, but they will all wear back eventually.Each oxidised silver piece has been sealed with a wax to prolong this beautiful dark patina but is still not resistant to wear.