Rhenium is a chemical element with symbol Re and atomic number 75. It is a silvery-white, heavy, third-row transition metal in group 7 of the periodic table. With an estimated average concentration of 1 part per billion (ppb), rhenium is one of the rarest elements in the crust. Rhenium has the third-highest melting point.

Atomic Weight: 525
Density:       52 g/cm3
Melting Point: 52
Boiling Point: 987