Chromium

Chromium is a chemical element with the symbol Cr. It is a steely-grey, lustrous, hard and brittle transition metal. Chromium is the main additive in stainless steel, to which it adds anti-corrosive properties.

The image reflects the toxic nature of the metal and its ‘mirror shine’ when polished.

Chromium is used to harden steel, to manufacture stainless steel (named as it won’t rust) and to produce several alloys.

Chromium plating can be used to give a polished mirror finish to steel. Chromium-plated car and lorry parts, such as bumpers, were once very common. It is also possible to chromium plate plastics, which are often used in bathroom fittings.

Chromium compounds are used as industrial catalysts and pigments (in bright green, yellow, red and orange colours).

Rubies get their red colour from chromium, and glass treated with chromium has an emerald green colour.