Made of sterling silver and oxidised sterling silver. The posts are made of sterling silver.
Brass oxidizes very fast & leads to discoloration of your jewellery. To clean it please give it a buff with the green then blue paper enclosed. Repeat as necessary. Be careful not to clean off any oxidation (black). To prevent water damage, keep jewellery in bag provided. For safe keeping, pierce earrings through bag and fasten butterflies on the outside
You can also clean it with a soft cloth and a metal cleaning agent such as Silvo/Brasso, or a generic jewellery cleaner. To avoid jewellery developing a dull appearance, try keeping them away from body lotions and perfumes. All jewellery must be removed when exercising, swimming and showering.