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.
Amber is fossilized tree resin (not sap), which has been appreciated for its color and natural beauty since Neolithic times. Much valued from antiquity to the present as a gemstone, amber is made into a variety of decorative objects. The abnormal development of resin in living trees (succinosis) can result in the formation of amber. Inclusions of other substances can cause amber to have an unexpected color. Pyrites may give a bluish color. Bony amber owes its cloudy opacity to numerous tiny bubbles inside the resin.