925 Sterling Silver is a combination of 92.5% pure silver and 7.5% of another metal, and it is the highest percentage of fine silver possible for jewelry subject to everyday wear. Fine silver (99.9% pure) is generally too soft and malleable for jewelry. Therefore, it is usually combined with copper to give it strength, while at the same time preserving both the ductility and beauty of its original form.
Ceramic is an inorganic, non-metallic, often crystalline oxide, nitride or carbide material. Some elements, such as carbon or silicon, may be considered ceramics. Ceramic materials are brittle, hard, strong in compression, and weak in shearing and tension. They withstand chemical erosion that occurs in other materials subjected to acidic or caustic environments. Ceramics generally can withstand very high temperatures, such as temperatures that range from 1,000 °C to 1,600 °C (1,800 °F to 3,000 °F).