 In this unit, we have been learning about lapis lazuli, which is a blue rock colored blue by the mineral lazurite, most commonly, but also mixed with various other components, oftentimes calcite and pyrite, as you can see in this fragment here. Lapis lazuli is used for carvings, as a blue stone for carvings. It's also used as a pigment. Now, in contrast to ochres, which have been used as a widely available, very low-cost, permanent type of pigments, the lapis lazuli has to go through quite a bit of processing in order to produce the pigments. So the various other components, in addition to the blue lazurite in the rock, need to be removed by processing. The rock itself is much less common to begin with and requires some more extensive mining processes and then much more labor-intensive, as you have seen, much more labor-intensive processing in order to go from the raw material. As you see here, we have some large fragments and some small chips and powder of the lapis lazuli itself to the variably processed and ultimately the blue ultramarine pigment that has been so prized throughout history. So one of the major factors that of course comes into our study of lapis lazuli as opposed to ochre, for example, is economic reality, economic reality for the artist. Ultramarine, the pigment that came from lapis lazuli, was called ultramarine because it came from over the sea. So it came from far away. The raw material itself was an expensive import. And then as you saw in the video with Randy Asplin processing the lapis into ultramarine pigment, it's a very painstaking process. And only about 2-4% by volume of this stone actually becomes the purest best grade pigment. And overall, you only get about 10% by volume that can be used for pigment. And this is a vial of ultramarine ash. This is the lowest quality of ultramarine derived from lapis lazuli. And it's still quite expensive, but it's valued because it is a rich blue with a translucency and sort of a sparkle to it. And you will have seen in some of the case studies the effect of this ultramarine pigment with gold leaf behind it and that wonderful luminosity of it. And of course, the most important figures in Renaissance paintings are the ones that have the greatest amount of this ultramarine pigment. And contracts often stipulated by volume and also by ultramarine grade how much would go in. For sculptures made of this stone, it was still a very high status material. And since it is relatively hard to work, remind me the hardness scale on this. A flat right? I think it's about a 6 or a 7. Okay, so it's pretty hard, close to what we encounter later on with rock crystal, for example. And so early cylinder seals made out of this were prized not only for how much more difficult it was to work. You had to have a more skilled artist working for a longer period of time, but also for this celestial blue color. And we find it being associated with the gods in early mythology and also with very expensive luxury items throughout the ancient world.