Hello, I'm Justin Rowland and welcome to another element special from Business Daily.

This is the series that explores those most basic substances of the modern global economy, the chemical elements.

And this week, it's a pair of metals that together have yielded possibly the most important substance of them all, steel.

One of them is, of course, iron, the main constituent of steel,

but it was thanks to another more obscure element that steel first became an affordable, mass-produced material 150 years ago.

Music mass-produced material 150 years ago. That element is manganese.

And it is still a critical ingredient in modern steelmaking.

The industry that delivers everything from skyscrapers to cars,

from railway lines to the oil drums you can hear being played right now.

Right, Professor Andrea Sella is brandishing a packet of rocket or arugler, as they'd call it, in America.

These are leaves for your salad because manganese lies at the heart of this stuff.

Of rocket.

Well, manganese is a transition metal, and often you kind of shrug your shoulders and you go,

oh my God, another metal. Who cares? Aren't they all the same?

And no. At the heart of photosynthesis is a little cluster called Photosystem 2. It's a little cluster of manganese and oxygen.

And that is the little molecular machine which actually transforms water and releases the oxygen from it.

So it's not just rocket arugula, it's all leaves. All plants contain this

manganese-based system. And the result is that manganese is at the heart of all oxygen production

in our world. And therefore, at the heart of all life. Now, of course, that process is central

to the world economy, but it's not how human beings routinely use manganese, is it?

No, manganese is something that we've used for a very, very long time

in the form of its ore, and that's this stuff here.

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