Material care -
GOLD-FILLED - 14k Gold filled is considerably durable and considered a lifetime piece of jewelry. This is NOT gold plated or gold dipped vermeil jewelry which can chip off over time with wear. It will never chip or flake off such as gold plated metals.
STERLING SILVER - Sterling silver jewelry is made with genuine silver.
Brass- Brass will tarnish over time for an "antiqued look". You can polish with toothpaste, by gently taking a drop of toothpaste and rubbing it on your piece of jewelry. Make sure it is paste, not gel.
TARNISHING - All precious metals will tarnish with wear. The best way to avoid tarnishing is to not wear your jewelry while you sweat, swim or shower. It doesn't mean you CAN'T wear your jewelry during those times- they will just require more polishing over time.