Stone Age blade fragments. Close-up of a collection of stone debris found during excavations at the Blombos cave site in South Africa. This site was made famous by the discovery of pieces of ochre engraved with abstract designs, 75000-year-old beads made from Nassarius shells, and bone tools thought to be around 80,000-years-old. These fragments include pieces of stone blades and the debris produced when the cave's inhabitants fashioned them from rocks and stones.