Galena is a naturally occurring lead sulfide (PbS) and is a very dark gray to black mineral. It was ground into a powder and mixed with other ingredients to create kohl, the black eyeliner that was so iconic in ancient Egypt.
While galena is a toxic substance, the Egyptians were aware of its potential risks and used it in very small quantities. They also mixed it with other ingredients, like soot, gum, and honey, which helped to reduce the risk of irritation.
It's important to note that modern makeup does not use galena.