And then they are fossilized over millions of years.

Latin'calx 'for'lime'

The dead have been covered with lime.

Limestone pie and hot melted silver.

But after some nagging, I got him to do that.

It looks beautiful.

The first tunnels date back to 60 B.C.

Now, this is the very interesting part.

We're not killing the colony we're taking a small core sample out of the top.

Maybe they could extract carbon dioxide.

Well, we have to take a little excursion, and we'll start in central Texas.

Ashes to ashes...

Ashes to ashes.

They shouldn't be there. And we called it Lost City.

Oh, let that be a lesson to you, Sanford.

So scientists also tend to get famous when they're much older.

like these.

ADAMS Ashes to ashes, dust to dust.

Ashes to ashes,dust to dust.

So that these don't just exist as one entity, we kind of chemically engineer them.

It's about 400 million years old.

A rolling stone gathers no moss.

Volcanic Ash

The dip slopes in the overlying limestone, the orientation of the flora, shallow waters...

I meant the motorcycle bar, but yes.

This is amazing. In the wake of all this,

Over on the eastern side it's gentle, as you can see.

To Gray

Oh, just a little.

He's grayblue.

According to the Roman scholar Pliny the Elder, citizens of the Empire believed that limestone from a quarry near Troy would dissolve flesh.

Four decades later, the world consumes between three and six barrels of oil for every one that it finds.

We made this game in 2007.

Then even the stones come alive.

But I told him no, I'm sorry, compromise in colors is gray, and we have enough gray to last us a lifetime.

And architect Christian Kerrigan has come up with a series of designs that show us how it may be possible to actually grow a limestone reef underneath the city.

I picked this up at MlT. It's a little younger.

Is there an ashtray in here?

The bones and the ashes.

And the ashtray.

It's going to be gray.

The birthstone of April is diamond.

Can you see, as the years pass by, child survival is increasing?

MT Nikola Tesla died on the 7th of January, 1943.

The rest is ash!