The Metals

Copper (Cu, atomic number 29) is a reddish transition metal with outstanding electrical and thermal conductivity. Regarded as the first metal humans deliberately worked, it is today an indispensable industrial commodity.

Gold (chemical symbol Au, atomic number 79) is a yellow, corrosion-resistant precious metal that has served for millennia as a store of value, a monetary metal and an engineering material.

Iridium (Ir) is a silvery-white platinum-group precious metal with one of the highest densities of any element (22.56 g/cm3, just behind osmium) and exceptional resistance to corrosion.

Osmium (Os, atomic number 76) is the densest naturally occurring element on Earth and belongs to the platinum group of metals.

Palladium (Pd, atomic number 46) is a silvery-white platinum group precious metal used above all as a catalyst in vehicle exhaust systems and in the electronics industry.

Platinum is a rare, silvery-white precious metal of the platinum group with atomic number 78 that, thanks to its exceptional corrosion resistance, catalytic properties and industrial versatility, ranks among the most valuable metals on earth.

The platinum group metals (PGMs) are six chemically related transition metals – platinum, palladium, rhodium, iridium, osmium and ruthenium – distinguished by exceptional corrosion resistance, high melting points and catalytic properties.

Precious metals are a group of chemical elements marked by high resistance to corrosion and oxidation, and they occur in nature largely native — that is, in pure metallic form.

Rhodium (Rh) is a silvery-white platinum-group precious metal used mainly as a catalyst in vehicle exhaust systems and for surface finishing; it ranks among the rarest and most expensive metals on Earth.

Ruthenium (Ru) is a rare platinum-group metal prized for its exceptional hardness and corrosion resistance, used chiefly in the electronics industry and as an alloying additive.

A semi-precious metal is a metal that shows some resistance to corrosion but does not possess the full chemical inertness of the precious metals.

Silver (Ag) is a bright-white precious metal with the highest electrical conductivity of any element, used both as an investment metal and across industry, photography and medicine.

White gold metals are the precious metals that give gold a silvery-white colour when used as alloying partners — chiefly palladium, platinum and nickel.