Brass is an alloy of copper and zinc. The proportions of zinc and copper can be varied to create a range of brasses with varying properties. For jewelry, the most commonly used percentages of copper and zinc is 67% and 33%. This mixture helps the brass become stronger and more durable than copper alone, which allows for superb electroplating quality, and thus, it is the perfect combination for fashion jewelry.
Jade is an ornamental rock. The term jade is applied to two different metamorphic rocks that are composed of different silicate minerals: nephrite and jadeite. Nephrite and jadeite were used from prehistoric periods for hardstone carving. Jadeite has about the same hardness as quartz. Nephrite is slightly softer, but is tougher (more resistant to breakage) than jadeite.