 Hi, I'm Maureen Feynman and the Geosciences Department at Penn State. I'm Heather McKeown-Brune and the Department of Art History at Penn State. In module one, we're going to be talking about the ochres. The ochres actually refers to a group of minerals of brightly colored pigments that are formed to take their color from oxides of iron and hydroxides of iron. And these oxides and hydroxides are typically suspended or mixed with clay minerals, maybe some calcite or some gypsum. Essentially they're rusty brightly colored muds and these minerals or these these muds then harden into a colorful rock that can then be powdered and ground down into powder form, cleaned up, and then used as the basis for pigments for art materials. As you can see, some of the ochres are more yellowish in color. Those are dominated by the iron oxyhydroxide limonite and give a more yellowish colored pigment whereas others are more orangish or even reddish in color. Those are typically colored by hematite iron oxide and those yield a more red colored pigment. So ochre is for art history an extremely important material because it is really humankind's first painting material. We have evidence that early humans were actually painting their bodies with ochre as early as 100,000 years ago in what archaeologists and anthropologists call early symbolically motivated behavior by at least 40,000 years ago possibly even earlier because the dates keep getting pushed every time they find something new and find a better more accurate dating system. But as early as 40,000 years ago we have cave paintings in areas of Spain and in France. Even earlier than that we have cave paintings and rock paintings in the African continent. So this is a really important sort of historical material and it's one that still is used today. It's incredibly plentiful, not that expensive and very, very saturated in terms of its color. So it's quite valuable not just for artists but also in industry.