The natural properties of gold: Gold, also known as Aurum, with the chemical symbol Au, has an atomic number of 79 and an atomic weight of 197. There are 22 known isotopes with mass numbers ranging from 183 to 204. The melting point of gold is 1063°C and its boiling point is 2808°C. Gold has a relatively high density, measuring at 19.32 ... at 20°C.