Platinum is a chemical element with the chemical symbol Pt and an atomic number of 78. Its name is derived from the Spanish term platina, which is literally translated into "little silver". It is a dense, malleable, ductile, precious, gray-white transition metal. Platinum has six naturally occurring isotopes.
Platinum is the rarest and most expensive precious metal – more so than either gold or silver. And platinum crystals are even rarer – so rare that, until a few years ago, they were considered to be the rarest objects on the face of the earth!
Osmium twinning / Osmium is a hard, brittle, blue-gray or blue-black transition metal in the platinum family and is the densest naturally occurring element, with a density of 22.59 g/cm3 (slightly greater than that of iridium and twice that of lead).