Rhenium - Re
Rhenium is the heaviest congener of manganese. It is a rare and rather inert metal. The finely divided metal is a black powder, as shown by the sample above. Larger pieces of the metal have a silvery appearance and the sintered form has a matte grey appearance. Both the sintered form and the bulk metal are shown in the picture below. The sheets of metal have a width of approximately 6 mm, the pellet of sintered rhenium is 0.75 grams. Purity of the sheets is 99.95%, purity of the pellet of sintered metal is 99.9%.
When the sintered form is studied in more detail, then one clearly sees fine shiny particles, as shown below.