Iron is by mass the most common element on Earth, forming much of Earth's outer and inner core. It is the fourth most common element in the Earth's crust. Pure iron is relatively soft, but is unobtainable by smelting. The material is significantly hardened and strengthened by impurities, in particular carbon, from the smelting process. A certain proportion of carbon (between 0.002% and 2.1%) produces steel, which may be up to 1000 times harder than pure iron.
Imitation Gold is a coating of metal whose color looks like 14k-18k gold, making jewelry more affordable but at the same time keeping the good quality. Imitation gold has a tint of red, and appears to have a reddish yellow hue.