18th birthday key creamOf all the birthday's (every year) the 18th is the most significant. The biggest significance of the 18th birthday is that it is the moment where someone turns into an adult, a key symbolises this. Made from Rhodium is a chemical element with symbol Rh and atomic number 45. It is a rare, silvery white, hard, corrosion resistant and chemically inert transition metal. It is a noble metal and a member of the platinum group. Silver is used for the trim,