A precious metal does not or nearly not connect with oxygen (rusting, or oxidizing). That’s why a precious metal always stays beautiful! This makes them incredibly suitable for making jewelry.
Gold and platina are the most famous examples of precious metal. These metals always stay beatiful. Silver is a little bit less precious, or noble, and will slowly connect itself to oxygen. Silver jewelry eventually will turn black. Polishing will let the old shine return. Metals like iron and copper will over time connect with oxygen, and form a brown or green rusty layer on the surface. At last these metals will completely dissolve.
Precious metals are tradionally used as a means of trade. This is because these metals are quite rare compared to other metals. They didn’t decrease in quality to soon and their worth was stable. Precious, or noble metals, were used as moneybill’s nowadays. Even when paper money was introduced, its worth was related to precious metals. The golden, silver and double standard.
Gold is a soft metal and is used as alloy for jewelry. The composition of the alloy determines the final color of the gold (yellow, white or rose gold). The melting temperature of gold is around 1100 degrees of Celcius.