Element 23 in our International Year of the Periodic Table elements series is vanadium. Vanadium is found in some steels to improve their hardness and is also behind the yellow blood of some animals.
Vanadium is famed for its many-coloured oxidation states (shown below). Vanadium(V) oxide is used to give ceramics a golden colour, while added to glass it gives a green or blue tint. It’s also used a catalyst in the industrial manufacture of sulfuric acid.
Vanadium also contributes colour to the blood of sea cucumbers. They have yellow blood due to the presence of vanabins, vanadium-binding proteins. Vanadium isn’t the only element that contributes to unusual blood colours, as this previous graphic shows.
Remember, you can keep track of all of the previous entries in this series on the site here, or on the Royal Society of Chemistry’s dedicated page.