In 2018, archaeologist found a stone with red lines drawn on it that is believed to be 73,000 years old - making it the oldest sketch ever found. The Blombos cave where the sketch was discovered also had Homo Sapien bone tools, teeth, engravings, and beads made from seashells. This finding may also have provided further information on Homo Sapiens use of symbols which is the foundation for mathematics and language. With the help of a microscope, scientists found out that the rock was painted using red ocher, a pigment that was often used in the prehistoric paintings.