Brass is an alloy of copper and zinc which has long been a popular material for adornment due to its bright gold-like appearance. Brass will naturally patina (darken) over time and can be sensitive to body chemistry.
As a rule, you should remove your jewelry when showering, avoid exposing your jewelry to pools & hot tubs, excessive sweat, perfume, sunscreen, hairspray, and any household chemicals.
The best way to keep your brass looking new is to store it in an air-tight container, keep away from moisture and chemicals, and clean regularly. To clean your brass you can use over-the-counter products such as Brasso, or you can use a variety of natural cleaners such as lemon and salt, plain old toothpaste, or even ketchup for a quick shine in a pinch!
Gold-filled jewelry is composed of a solid layer of gold mechanically bonded to a base of brass or silver. Most high quality gold-filled pieces have the same appearance as high-carat gold and gold-filled items, even with daily wear, can last 10 to 30 years though the layer of gold will eventually wear off exposing the metal underneath. The layer of gold on gold-filled items is 5 to 10 times thicker than that produced by regular gold plating. Gold-filled jewelry typically has .5% gold alloy as compared to .05% (or less) for gold-plated.
Gold-filled does not de-laminate or peel like plated or "dipped" products. Nor does it tarnish as readily as silver. Many owners find that they never have to clean gold-filled items at all. However, from time to time your jewelry may become dirty from everyday wear. To clean gold-filled it is best to use mild soap and water. Hot weather and water will not damage the material.
To make gold-plated pieces, an electric current is used to negatively charge the base metal and positively charge a solution containing gold ions. The positive gold ions are attracted to the negative charge of the core metal, slowly forming a layer of gold on top of the core. Basically, gold plating is a minuscule layer of solid gold applied to a brass base. The plating does not compose any measurable proportion of the products total weight. It is estimated to be 0.05% or less of the metal product. Gold plating will generally wear off more quickly and expose the brass base product. It does not stand up to heat, water or wear over time.
The number one rule for cleaning gold-plated jewelry is to never scrub it. It is also very important to not expose gold-plated jewelry to water or chemicals. Should your piece become tarnished or dirty, you can clean it with a cotton ball or a very soft cloth to remove any dust and dirt. Gently rubbing the surface of your gold plated jewelry using a soft jewelry cloth also helps restore shine. If your jewelry needs more cleaning you may clean it with warm, soapy water and dry thoroughly.