A one gram sample of Iridium, which I bought myself for another video.

And here I've got a big piece of a radium.

This weighs 3.8 kilos and Iridium is the second densest metal that exists.

Only Oz me, um, is denser, but the difference in density is so small that you wouldn't really tell the difference.

It has one of the highest melting points as well.

On DDE.

I'm really impressed by this.

It looks just like an ordinary piece of metal, but it's really quite heavy.

I've got this sample because I'm a Johnson math in noble metal plant where they actually process this material.

They take the sponge which comes from the mines, where they dig up the rocks and process it and turn it into metal objects.

And this piece of rod is one of the intermediate stages.

To get this far, one has to process about six or 700,000 tons of rock, a huge amount of rock, nearly a 1,000,000 tons of rock.

Just to make this, why should people want to radium?

It's very useful because it's high melting point and its strength because of its high melting point, you can make it into crucibles.

This is a very little crucible, but if you want of you handle liquids at high temperature 2000 degree centigrade.

You have no choice.

You have to use an iridium crucible.

So here is quite a small one might make quite a good vodka glass, actually.

But the really crucibles that people use safer growing crystals of silicon and so on are really much bigger.

This is a sheet of a radium for making a crucible.

You make the crucible in two pieces.

You have a smaller piece here.

That's the bottom.

You cut out a circle, and then this piece is wrapped around to form the sides.

This piece of metal, which is really very heavy again, will be rolled up on dhe welded on what's unusual about this seat of metal.

It's not very thick, but it's absolutely rigid.

It doesn't bend at all.

If you had a piece of steel like this, it would be getting to feel slightly bendy.

You can feel that it has unusual properties, is not like a metal I felt before, and it's very heavy on this Density makes it very hard and rigid, but you can imagine how much this is worth because the price of a radium is approaching £800 announce.

So these are very expensive materials on DDE.

We're in a metal free zone.

We're not allowed to bring in any metal to make sure that nobody steals.

And if you don't have any metal, it makes it easy to screen you as you go out.

You have nothing metallic, nothing.

That's an electrical conductor, so it's easy to screen.

If you have lots of bits of metal, you might be able to sneak something through.

So when I came here, everything went my favorite pen, even my belt from my trousers.

This is something I've never seen before.

This is where somebody actually chooses the name of an element.

So if you look down here, I should incline to call this metal iridium.

So this is the first time that anybody ever wrote down the word Iridium.

Now, of course, he might have written it in his notes, but this is the first official record of anybody writing the word iridium.

One of the other areas where you have very high temperatures are in the tips of spark plugs.

You know, you put spark plugs into the tops of cylinders of petrol engines, and when the spark ignites, the explosion ignites the fuel air mixture.

Then you get very high temperature, and you don't want it to rode away.

You want the sparkplug toe work for thousands, if not hundreds of thousands of miles, and you do this by putting in a tiny rhythm tip thes air.

The tips of the spark plugs like that they're really tiny on DDE.

It's important distress that modern technology depends on making these tiny, tiny components of a radium on getting them in the right place.

So you use the metal you need at the really important point in the spark plug.

It's must less important what you make the nut from or the contact at this end.

But you've got to get it really right just there, and then you get the maximum performance.

I also like these here.

These are the grains of iridium that are made from the sponge that comes from the bine on the first stage of the processing is making these rather irregular size grains, which can then be melted again and cast into ingots before they make bars like this.

Earlier on, we were shown Ah, whole tub full of grains of a radium, and I could actually run it through my hands.

Something I'll never do again.

Probably, but I really just want to pick this up again.

Make the most of it.

Well, I've got the time.

It's like your periodic videos, Mace.

For once, I can keep Brady and Order.

Iridium is found in very low concentrations on our planet, but it's found in quite high concentrations on asteroids and meteorites on Dhe.

A physicist, Luis Alvarez in the 19 early 19 eighties, pointed out that there is a very thin layer geological layer in the so called K T boundary in the rocks from 65 million years ago, which is rich in Iridium.

It has 100 times the concentration of iridium, and this is believed to come from the asteroid that hit the Earth and killed all the dinosaurs because it vaporized and put a layer of iridium around the world.

And by tracing this tiny layer of rock which contains high levels of iridium, the whole theory of how the dinosaurs disappeared from the world was developed.

It wasn't the iridium that killed the dinosaurs.

They were killed by the explosion.

But it was the iridium that left the signature that let us understand what had happened.

You wouldn't write English quite like that.

Nowadays, this metal iridium here is the name Iridium.

And here, he says, from the striking variety of colors, which it gives while dissolving in.

And I can't read the name of the acid.

It could be muriatic acid.