The Blue Once Worth its Weight in Gold | BBC Earth Science

[00:00:00]I'm about to enter a very different world.

[00:00:10]David Margolis is an artist, historian, and devotee of the color blue.

[00:00:19]In his London studio, he works with some of the rarest minerals and pigments on Earth.

[00:00:26]Among them all, the most spectacular are the blues.

[00:00:31]And one blue in particular takes pride of place on the shelves.

[00:00:40]>> This is a piece of um lapis lazuli that's come from the one mountain in Afghanistan.

[00:00:46]>> So, the the important thing here is this blue color, and that is lapis lazuli.

[00:00:50]>> It [music] is It was the most precious and most expensive of all the pigments.

[00:00:55]>> There aren't many blue things in nature, so this must have been a spectacular thing to display and to find.

[00:01:01]>> Someone had walked through the mountains of Afghanistan and come across blue stone, and it makes me wonder whether they believed that the sky had fallen to the Earth and turned to rock.

[00:01:17]>> I love that idea, the sky that had fallen into a rock. That's exactly what it looks like, isn't it?

[00:01:22]>> [music] >> The color is so stunning. I can imagine the impact it must have made when lapis first arrived in Europe, when trade routes from the East opened up.

[00:01:38]>> It was seen as extremely valuable um in Renaissance Italy. It was so expensive, it was the equivalent of the price of gold.

[00:01:45]>> To have this was a status symbol, and the most visible way of having it was to put it on a painting. Because you could paint this color onto a big canvas and show that you had this commodity. So, it's not a subtle way of displaying your status. It's saying for everyone to see.

[00:01:59]>> it's subtle at all. I think the most important aspect is that lapis does have a slightly mystical quality.

[00:02:11]So, when it came to painting, [music] quite often the blue was used to paint the robes of Mary.

[00:02:19]Probably the most famous [music] artist to have used it is Titian.

[00:02:25]>> There's something entrancing [music] about this color.

[00:02:28]But to discover what it can tell us about our planet, I need to do what painters do and get [music] right inside this rock.

[00:02:38]An artist is presented with a lump of this rock and they have to make paint out of it.

[00:02:42]What do they do?

[00:02:43]>> They hammer it.

[00:02:44]>> How very sophisticated.

[00:02:46]>> [laughter] >> Hammer it until it gets smaller and smaller.

[00:02:49]>> [snorts] >> That's quite satisfying this.

[00:02:56]>> [music] >> This is the first time it's been a color cuz this has never seen daylight before.

[00:03:01]That [music] bit of rock I've just smashed has just become a color for the first time. So, the next one along So, now we've got lots of broken up little bits [music] and you can start to see blue powder.

[00:03:11]>> That's right.

[00:03:11]>> And that's what the pigment is. It's the powder when it becomes a powder.

[00:03:14]>> That's right.

[00:03:18]>> Oh, that's a horrible noise.

[00:03:20]It's such a horrible noise.

[00:03:22]>> And you might smell it as well.

[00:03:24]>> Oh, there's a really strong smell [music] of sulfur.

[00:03:28]>> It is sulfur. Sulfur is what makes the rock blue.

[00:03:31]>> And then the final stage when it's broken down is >> [music] >> is what we've got in the the last one here. This is the bluest thing I've ever seen.

[00:03:41]It's the chemistry of this rock that creates [music] its color.

[00:03:45]Sulfur more often produces yellowish compounds. This is lovely lovely stuff.

[00:03:52]But in lapis lazuli, the unique [music] combination of sulfur with other elements produces this deep, rich blue we call ultramarine.

[00:04:02]>> [music] >> And this is it. This is the final step.

[00:04:15]The blue powder has been mixed with oil and some wax, and it's a paint.

[00:04:21]And so this rock that looks like it fell from the sky is becoming sky all over again.

[00:04:29]>> When we look at this, we just see a [music] blue rock.

[00:04:32]But the secret to that color is hidden in the atoms that make this up.

[00:04:38]But the atoms themselves aren't enough.

[00:04:41]To get this, you need to transform them.

[00:04:44]For a transformation to this dramatic blue, you need the sorts of pressures and temperatures [music] with which planets are forged.