Chromium - colourful and shiny

Chromium is a transition metal that gives colour to precious jewels, the shine to your car fender and your kitchen bench, but can also be a killer. All this and more in ep 21 of Elemental with Allan Blackman from AUT.

Chromium, the element, gives us colour and shine - and helped Julia Roberts win an Oscar in 2000 for the movie Erin Brockovich.

Chromium is the red in rubies, the green in emeralds and the pink in sapphires.

It is the shine on your car fender and your stainless steel kitchen bench.

Chromium III is widely used to tan leather*, while chromium XI (hexavalent chromium) has been used in textile dying and corrosion resistant coatings, and is very carcinogenic.

The story of chromium the transition metal (Cr, number 24) with Professor Allan Blackman from AUT.

*CLARIFICATON:

Chromium XI is not used in leather tanning."Basic Chromium (III) Sulphate has been used for many decades to tan over 90 percent of the world's leather. It reacts with collagen covalently via the carboxyl groups associated with glutamic and aspartic acids to give a hydrothermally stable substrate, or leather." Information courtesy of the New Zealand Leather & Shoe Research Association

Go to this episode on rnz.co.nz for more details