Rhenium is a transition metal that has a grey white color in its natural solid state. This recently discovered mineral has an extremely high melting point and is also very dense. Rhenium has an atomic weight of 186.207, a melting point of 5767 °F, and a boiling point of 10105 °F. Some common uses of rhenium include: as a component in the process used to create lead free, high octane, gasoline, as a component in some types of alloys, as a catalyst for certain chemical reactions, and as a component in thermocouples.